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Delaware · Northern Delaware · Philadelphia Metro · #118 Most Populous County in the US
New Castle County, Delaware
Delaware's most populous county and home to Wilmington, the corporate capital of America - from the Brandywine Valley's chateau country and the University of Delaware in Newark to the chemical industry corridor along the Delaware River. Property tax, courts, public records, and senior services for New Castle County residents.
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New Castle County's assessment ratio means effective tax rates are low — but incorrect appraisals still cost money. Ownwell manages the appeal with no upfront cost.
Office: New Castle County Emergency Operations – (302) 395-2700 | nccde.org
Alert System: DE-Alert; CodeRED; New Castle County NCC ALERT; NOAA Weather Radio
Shelter Info: Multiple shelter locations; New Castle County government complex; American Red Cross Delaware – (302) 655-5171
FEMA Region: Region 3
Notes: Northern Delaware county; Wilmington is the county’s largest city (and Delaware’s largest city) and the county seat; hurricane/tropical storm risk (significantly elevated for the Delaware Valley – Hurricane Sandy 2012 caused major flooding on the Christina River and Delaware River in Wilmington; severe coastal surge affected Delaware Bay shoreline); nor’easters; flooding (Christina River, Brandywine Creek – both flow through Wilmington; historic flooding has been severe); petrochemical and industrial hazards (Wilmington and the Delaware River corridor have significant industrial facilities including the Port of Wilmington and nearby refinery infrastructure); Delaware Memorial Bridge (major I-295 crossing over the Delaware River – a critical infrastructure asset requiring emergency management protocols); Amtrak’s Northeast Corridor runs through the county
Roads & Utilities
ROADS & TRANSPORTATION
County Roads: New Castle County Department of Special Services – (302) 395-5700 (limited county road function; most roads maintained by DelDOT)
State Roads: DelDOT – (302) 760-2080
Transit: DART First State (comprehensive bus network in Wilmington area); Amtrak (Northeast Corridor – Wilmington Station is a major Amtrak stop on the Washington DC-New York-Boston corridor; one of the busiest regional rail stations in the Mid-Atlantic); SEPTA (Southeastern Pennsylvania Transportation Authority – serves portions of northern New Castle County; R2 rail line connects Wilmington to Philadelphia Airport and 30th Street Station); Delaware Express/Shuttles
Airport: Philadelphia International Airport (PHL – accessible via I-95; 20 miles north); Wilmington/Chester County Airport (ILG – limited commercial service)
Notes: I-95 (the Northeast Corridor’s defining highway – runs through Wilmington; extremely heavy freight and commuter traffic; the I-95 corridor is Delaware’s most significant transportation asset); I-495 (Wilmington bypass – the Delaware Memorial Bridge approaches); I-295 (the Delaware Memorial Bridge – twin suspension bridges over the Delaware River connecting Delaware to New Jersey; a critical regional bridge); US-13 (north-south through the county); Amtrak’s Wilmington Station is one of the most significant Mid-Atlantic Amtrak stations – the Northeast Corridor serves it with multiple trains daily; SEPTA’s R2 line extends into Delaware, a rare interstate rail commuter connection; Wilmington is about 30 minutes from Philadelphia by rail
Business & Permits
BUILDING & PERMITS
Office: New Castle County Department of Land Use – (302) 395-5400 | nccde.org/land-use
Services: County permits for unincorporated areas (most of the county outside Wilmington city); Wilmington (city – separate; significant urban redevelopment), Newark (separate; active – University of Delaware campus), New Castle, Middletown (one of the fastest-growing towns in Delaware – separate, very active), Bear, Glasgow, Hockessin, Pike Creek separate
Notes: New Castle County is Delaware’s most active building county; Middletown (southern New Castle County) is one of the fastest-growing communities in the Mid-Atlantic – enormous residential and commercial development as Philadelphia and Wilmington sprawl southward; Newark’s University of Delaware campus drives significant development; the Christiana Mall area (Newark/Bear) is a major commercial development hub; Wilmington’s urban core is the focus of significant redevelopment investment (WSFS Bank’s move, Chemours headquarters, Incyte Pharmaceuticals)
Veterans Services
VETERANS SERVICES
Office: New Castle County Veterans Affairs – (302) 395-2300
State: Delaware Division of Veterans Affairs – (302) 739-2792 | veterans.delaware.gov (state programs including a Delaware veterans home in Milford)
VA Medical: Wilmington VA Medical Center – (302) 994-2511 (full-service VA hospital; affiliated with Jefferson University Health; primary VA hospital for Delaware and southern New Jersey; excellent programs)
Services: Full range; Wilmington VAMC is Delaware’s primary VA hospital; active VSO chapters in Wilmington and throughout the county
Notes: Wilmington VAMC is Delaware’s only full VA hospital and serves a large region; the VA’s affiliation with Jefferson University Health creates strong academic medicine partnerships; New Castle County has a significant veteran community; Wilmington’s veteran programs include supportive housing given the city’s affordability challenges
Libraries
LIBRARIES
System: New Castle County Libraries – libraries.delaware.gov (state system; all Delaware public libraries); Wilmington Library (city – separate and excellent); Newark Free Library; Pike Creek Branch; Bear-Glasgow Branch; multiple branches throughout the county
Services: Books, e-books, public computers, Wi-Fi, genealogy (Delaware Public Archives in Dover supplements), maker spaces, children’s programs; Hagley Museum and Library (Wilmington – extraordinary industrial history library); Delaware Historical Society (Wilmington)
Notable: Hagley Museum and Library (on the Brandywine River – the former E.I. du Pont de Nemours gunpowder works; now a world-class industrial history museum and research library; one of the finest industrial heritage sites in the US); Delaware Historical Society Research Library (Wilmington – excellent Delaware and Mid-Atlantic genealogy and history collections)
Notes: Wilmington’s library ecosystem is enriched by the Hagley Museum’s research library (one of the finest industrial history archives in North America) and the Delaware Historical Society; the Hagley site itself (along the Brandywine) is remarkable – the gunpowder mills, workers’ community, and the original du Pont family residence are all preserved; the University of Delaware’s Morris Library is a major research library accessible to the public for reference use
Parks & Recreation
PARKS & RECREATION
State Parks: White Clay Creek State Park (Newark – excellent hiking, fishing, mountain biking in the Brandywine Valley landscape; the White Clay Creek Preserve extends into Pennsylvania; significant wildlife; excellent trail running); Lums Pond State Park (Bear – Delaware’s largest freshwater pond; boating; camping; family recreation; the Lums Pond Adventure Course is popular); Bellevue State Park (Wilmington – former duPont estate; equestrian; walking; gardens)
Regional/County: Brandywine Creek State Park (Delaware’s finest state park – Brandywine Creek corridor; bald eagle nesting; tidal fresh marsh; tulip poplar old growth; excellent birding; the creek is also the site of some of Andrew Wyeth’s paintings); Wilmington’s Brandywine Park (Frederick Law Olmsted-designed; the Brandywine Zoo; beautiful creek corridor through the city; the Alapocas Run State Park adjacent); Fort Delaware State Park (Pea Patch Island – accessible by ferry from Delaware City; a Civil War island fort that held Confederate prisoners; excellent birding on the island – one of the largest great blue heron and egret rookeries on the East Coast; remarkable combination of Civil War heritage and outstanding wildlife)
Cultural: Nemours Estate (Wilmington – Alfred I. du Pont’s magnificent French-style estate; the largest French formal garden in North America; extraordinary mansion open for tours; a genuinely world-class estate experience); Winterthur Museum (Wilmington/Greenville area – Henry Francis du Pont’s extraordinary collection of American decorative arts; the finest collection of American furniture, silver, ceramics, and textiles in the world; the gardens are extraordinary; one of the genuinely world-class art and design museums in the Mid-Atlantic); Delaware Art Museum (Wilmington – outstanding collection including the finest collection of Pre-Raphaelite British art outside the UK; important American illustrators including Howard Pyle and N.C. Wyeth – both Wilmington-connected); Brandywine River Museum (Chadds Ford, PA – just across the state line; the Wyeth family museum – one of the finest American art experiences in the Mid-Atlantic); Longwood Gardens (Kennett Square, PA – 30 minutes away; one of the world’s premier public gardens – a visit from Delaware is standard); Hagley Museum and Library (Brandywine River – the former du Pont gunpowder works; extraordinary industrial heritage)
Notes: The Wilmington/New Castle County area’s concentration of exceptional cultural institutions (Winterthur, Nemours, Hagley, Delaware Art Museum – all du Pont family legacy institutions) is extraordinary for a metropolitan area of its size; Winterthur’s collection of American decorative arts is genuinely the world’s finest – the 90,000-object collection spans 400 years of American craftsmanship; Nemours Estate’s French formal garden (the largest in North America) is breathtaking; Fort Delaware’s combination of Civil War history and extraordinary wildlife (the great blue heron and egret rookery is one of the East Coast’s most significant) is unique; the Brandywine Valley’s artistic legacy (N.C. Wyeth, Andrew Wyeth, Jamie Wyeth all painted these landscapes) gives the area a distinctive artistic identity
GIS & Maps
GIS & MAPS
GIS Portal: New Castle County GIS – nccde.org/gis; Delaware FirstMap (maps.delaware.gov); Brandywine watershed GIS; DNREC coastal maps; Delaware Memorial Bridge infrastructure maps; Amtrak/I-95 corridor mapping
Notes: New Castle County has an active GIS system; Delaware Memorial Bridge corridor mapping; Brandywine and Christina River watershed mapping; Middletown development tracking; Christiana Mall area commercial GIS
Animal Services
ANIMAL SERVICES
Shelter: Delaware Humane Association (Wilmington – (302) 571-0111 | delawarehumane.org; major regional humane organization); New Castle County Animal Services – (302) 395-2800; City of Wilmington Animal Control
Services: Stray intake (large volume), adoptions, owner surrenders, spay/neuter, microchipping; wildlife management (white-tailed deer; coyotes; red foxes; Fort Delaware colonial waterbird colonies; Brandywine Creek wildlife)
Notes: Delaware Humane Association is an excellent organization; Fort Delaware’s great blue heron and egret rookery (hundreds of nesting pairs on Pea Patch Island) is managed through the Delaware State Parks system; Brandywine Creek supports excellent wildlife (bald eagles nesting, osprey, great blue herons, river otters returning); urban wildlife challenges in Wilmington (raccoons, opossums, Canada geese in city parks)
Environmental & Waste
ENVIRONMENTAL / WASTE MANAGEMENT
Solid Waste: Delaware Solid Waste Authority (DSWA) – (302) 739-5361 | dswa.com (statewide system with Cherry Island Landfill in Wilmington area; Delaware Environmental Institute)
Environmental: Delaware DNREC – (302) 739-9000 | dnrec.delaware.gov (comprehensive state environmental agency); EPA Region 3; Brandywine Valley Association (bi-state conservation organization)
Key Issues: Christina River contamination (the Christina River through Wilmington carries significant urban stormwater and historic industrial pollution; ongoing remediation and restoration; the Riverfront Wilmington development is rebuilding on former industrial brownfields); Wilmington drinking water (the Brandywine Creek provides much of Wilmington’s water – the Brandywine filtration plant is a critical facility); Delaware City refinery (PBF Energy’s Delaware City Refinery – one of the East Coast’s significant petroleum refineries; air quality monitoring in the surrounding community); Port of Wilmington environmental compliance (the deepest East Coast port south of New York; handles fresh produce, automobiles, and other cargo; dredging and sediment management); lead paint in Wilmington housing (Wilmington has some of the nation’s highest childhood lead exposure rates due to pre-1978 housing stock with lead paint – a persistent public health emergency; extensive remediation programs)
Notes: The Winterthur/Hagley/Nemours estate landscapes along the Brandywine represent some of the finest preserved industrial-era landscapes in the US – the du Pont family’s extraordinary wealth (from their gunpowder manufacturing monopoly) created both the industrial heritage and the estate gardens; the Brandywine Creek watershed is the focus of significant conservation investment by the Brandywine Valley Association and DNREC; Wilmington’s childhood lead poisoning crisis has been a persistent public health emergency – the concentration of older housing stock with intact lead paint in lower-income neighborhoods creates exposure risks that affect child development; Delaware has been a national leader in lead paint remediation policy; the Delaware City Refinery’s air quality management is an ongoing environmental justice concern for communities near the facility; Delaware’s small size allows for unusually efficient statewide environmental management through a single agency (DNREC) rather than fragmented county agencies
About New Castle County
New Castle County is Delaware’s most populous county and the 118th most populous in the United States, covering 426 square miles of northern Delaware from the Delaware River south toward the state’s middle tier. It encompasses Wilmington (Delaware’s largest city), Newark (home to the University of Delaware), and the suburban and rural communities of the Brandywine Valley.
Wilmington (population ~70,000) is known as “The Corporate Capital of America” – a title earned by Delaware’s Court of Chancery and business-friendly corporation laws that have made it the legal home of more than 60% of Fortune 500 companies. The city itself is the financial and legal services center of Delaware, home to major banking operations (including JPMorgan Chase, Bank of America, and Barclays credit card processing centers), law firms, and corporate services companies. The DuPont company – which defined Wilmington’s industrial identity for nearly two centuries – has undergone significant corporate restructuring but remains symbolically central to the city’s identity.
Greenville and Centreville are unincorporated communities in the Brandywine Valley corridor north of Wilmington – home to some of the most significant private estates in the mid-Atlantic, including the Winterthur Museum (the former du Pont estate, now one of the premier decorative arts museums in the country), Longwood Gardens (across the state line in Pennsylvania, owned by Pierre du Pont), and numerous other du Pont family properties.
Newark (population ~33,000) is home to the University of Delaware (founded 1743, enrollment ~24,000) – the county’s major academic anchor and the dominant economic and cultural institution of northern Delaware outside of Wilmington’s financial sector.
Middletown (population ~22,000) is New Castle County’s fastest-growing community, drawing families from the Wilmington and Philadelphia metros seeking relatively affordable housing and newer school facilities along the Route 301 corridor.
The Delaware Memorial Bridge – twin suspension bridges carrying I-295 across the Delaware River to New Jersey – anchors the county’s eastern transportation infrastructure and its connection to the Philadelphia and New Jersey markets.
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Browse every category and topic available for this county.
New Castle County uses a base year assessment system – properties are assessed at values tied to a 1983 base year. Current market values can be significantly higher than assessed values. The county property tax rate is among the lowest in the region, though municipal and school district rates add to the total burden.
The appeal process: File with the New Castle County Board of Assessment Review at 87 Reads Way, New Castle, DE 19720, phone 302-395-5520. Delaware’s appeal process is generally more straightforward than neighboring Pennsylvania and New Jersey.
Delaware has no estate tax and no inheritance tax – one of only a handful of states with neither. Assets pass at death subject only to federal estate tax above $13.61 million (2025). Delaware’s favorable tax environment is a significant driver of retirement relocation from Maryland, New Jersey, and Pennsylvania.
Delaware’s overall tax advantage: Delaware also has no sales tax, no personal property tax on vehicles, and relatively low income tax rates for retirees – making New Castle County particularly attractive for retirement planning from higher-tax neighboring states.
OWNWELL CTA: New Castle County base year (1983) assessment – significant gap between assessed and market value creates appeal context. No DE estate or inheritance tax. Delaware’s overall tax-friendly environment. Ownwell manages the appeal with no upfront cost.
Recommended
New Castle County base year (1983) assessment - significant gap between assessed and market value creates appeal context. No DE estate or inheritance tax. Delaware's overall tax-friendly environment. Ownwell manages the appeal with no upfront cost.
Courts & Legal
Courts & Legal
Court of Chancery and Probate: Delaware’s Court of Chancery is internationally famous as the preeminent corporate law court in the United States – virtually all major corporate litigation is filed here. For residents, probate matters are handled by the Register of Wills in each county. The New Castle County Register of Wills at 500 N. King Street, Wilmington, DE 19801, phone 302-255-0850, handles estate administration, wills, and guardianships.
Superior Court: The New Castle County Superior Court at 500 N. King Street handles major civil and criminal matters.
Recorder of Deeds: The New Castle County Recorder of Deeds at 87 Reads Way, New Castle, phone 302-395-7700, maintains all real property records. Delaware land records are searchable online.
Senior Services
The Delaware Aging Network and the New Castle County Department of Community Services serve the county’s senior population. The Division of Services for Aging and Adults with Physical Disabilities (DSAAPD) at 1901 N. DuPont Highway, New Castle, phone 302-255-9390, coordinates in-home services, caregiver support, nutrition programs, and transportation. The Wilmington Senior Center and suburban centers across the county provide programming and case management.
Recommended
Assisted living, memory care, and independent living across New Castle County - from Wilmington and the Brandywine Valley to Newark, Middletown, and the Route 40 corridor.
Genealogy
County-level record sources
New Castle County Register of Wills (probate/estate case files – see Probate section above); historical New Castle County wills back to 1682 have been separately compiled (“A Calendar of Delaware Wills, New Castle County, 1682-1800”).
New Castle County deed books run from Book A (1673) through Y-50 (1951) – among the oldest continuous county deed records in the country.
A genuine Delaware quirk worth knowing: the colony (later state) was historically subdivided below the county level into “hundreds” – an old English land division, smaller than a county and larger than a tithing, once used for tax assessment, and for judicial/legislative districts. Hundreds still appear in older Delaware genealogical and property records and can be a useful search term for pre-20th-century research.
Local societies
Delaware Genealogical Society, meets in the Wilmington area (New Castle County) and supports research days at the Delaware Historical Society Research Library.
Delaware African-American and Hispanic Genealogical Society (DEAAHGS), P.O. Box 7205, Wilmington, DE 19803.
Probate & Estate
Losing someone and having to deal with courts and paperwork at the same time is hard. This section won’t make that easier, but it should tell you what to expect, what it costs, and where to go – so at least you’re not walking in blind.
Where to go
Register of Wills, New Castle County New Castle County Government Center, 800 N. French Street, 2nd Floor, Wilmington, DE 19801 (302) 395-7800
Hours: Monday–Thursday 8:00 a.m.–3:30 p.m., Friday 8:00 a.m.–3:00 p.m. (closed for lunch daily noon–1:00 p.m.). Phone lines staffed until 4:00 p.m. Evening appointments available by request at the Appoquinimink Public Library (204 E. Main Street, Middletown, DE) on the first Wednesday of each month, 4:00–5:00 p.m., and at the Hockessin Library.
Delaware’s Register of Wills is a branch of the Delaware Court of Chancery – each of the state’s three counties has its own Register of Wills office, and there is no separate statewide probate court.
Step 1: figure out which path applies
Delaware has NOT adopted the Uniform Probate Code; its probate procedures are set out in Title 12 of the Delaware Code.
Small Estate Affidavit – a recent, significant change: for anyone who died on or after June 10, 2026, the threshold is $50,000 or less in personal property with no solely-owned real estate. For deaths before June 10, 2026, the older $30,000 threshold still applies. (Delaware Governor Matt Meyer signed House Bill 333 on June 10, 2026, raising the threshold from $30,000 – unchanged since 2005 – to $50,000, effective immediately and non-retroactively.) This route avoids formal probate administration entirely.
Full Probate Administration – required when the estate exceeds the applicable small-estate threshold, or when the decedent owned Delaware real estate solely in their own name (or as a tenant in common).
If using the small estate affidavit
Confirm the decedent’s date of death to determine which threshold applies ($30,000 for deaths before June 10, 2026; $50,000 on or after).
Confirm the estate’s personal property (excluding jointly-held assets, beneficiary-designated accounts, and other non-probate property) falls at or under the applicable threshold, and that the decedent owned no solely-held Delaware real estate.
Complete the Small Estate Affidavit mail-in request form, available from the Register of Wills’ Forms page.
Submit it to the Register of Wills for the county where the decedent lived.
Once certified, the affidavit gives the named inheritor legal authority to collect and transfer the decedent’s assets directly – any person or institution holding the property is required to release it upon presentation of the certified affidavit.
If full probate administration is required
File a Petition for Authority to Act as Personal Representative (Form 1) with the Register of Wills to admit the will (if any) and request appointment.
The Register of Wills issues Letters Testamentary (with a will) or Letters of Administration (without one).
New Castle County mandates electronic filing for most probate documents through the File & Serve Delaware system.
The personal representative inventories the estate, notifies creditors, pays valid debts and taxes, and files an accounting.
Once approved, the estate is closed and remaining assets are distributed to heirs and beneficiaries.
What it costs
Probate fees are generally calculated based on the value of the estate, set by the Register of Wills fee schedule.
No Delaware state estate tax or inheritance tax – the state repealed its estate tax (which had applied as a “pick-up tax” tied to the old federal credit).
A surviving spouse is entitled to an elective share of one-third of the decedent’s augmented estate, protecting against disinheritance.
If a Delaware resident also owned real property in another state, that state requires a separate ancillary probate proceeding – Delaware’s Register of Wills has no authority over out-of-state real estate.
Probate filings, estate administration, and guardianship matters are handled by the following office(s):
Register of Wills / Orphans Ct
500 N. King St., Wilmington, DE 19801
(302) 255-0800
Elections & Voting
Voter registration, polling locations, and elections information are handled by the following office(s):
DE Dept of Elections — NCC
905 S. Governors Ave., Dover, DE 19904
(302) 577-3464
Health & Human Services
Offices & Contacts
Health services, social services, and assistance programs are handled by the following office(s):
DE Health & Social Services
(302) 255-9040
DE Medicaid / DMAP
(302) 255-9500
DE SNAP/Cash Assistance
(302) 577-4400
VA Medical Center
1601 Kirkwood Hwy., Wilmington, DE 19805
(302) 994-2511
Division of Public Health
dhss.delaware.gov/dph
Christiana Care Health
christianacare.org (major health system — Christiana Hospital)
Nemours Children's Health
nemours.org (pediatric health system)
Public Health Information
PUBLIC HEALTH
Office: New Castle County Health Department (limited function); Delaware Division of Public Health – (302) 744-4700; Wilmington Health Department (city – separate and active)
Services: Comprehensive state-level health department; immunizations; WIC; STI/HIV testing; environmental health; restaurant inspections; epidemiology; lead paint poisoning prevention (significant in Wilmington’s older housing stock)
Hospital: ChristianaCare (Christiana Hospital – Newark; (302) 733-1000; Level I trauma; the primary hospital for Delaware and the most comprehensive hospital in the state; nationally ranked; major teaching hospital affiliated with Jefferson University); Wilmington Hospital (ChristianaCare – downtown Wilmington); St. Francis Hospital (Wilmington – Trinity Health); Nemours Children’s Health (Wilmington – Alfred I. duPont Hospital for Children; one of the nation’s finest children’s hospitals; ranked in the top 10 nationally in multiple specialties)
Notes: ChristianaCare’s Christiana Hospital is Delaware’s finest hospital – it is the only Level I trauma center in the state and provides sophisticated services for the entire Delmarva Peninsula and southern New Jersey; Nemours Children’s/Alfred I. duPont Hospital for Children is one of the finest children’s hospitals in the US – its orthopedics and genetics programs are nationally recognized; Wilmington has significant health disparities (some of the highest rates of childhood lead poisoning in the nation; gun violence-related trauma; behavioral health challenges); the opioid crisis has severely impacted Wilmington; Delaware has historically been a leader in opioid treatment policy
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