Boundary Atlas

ZIP code 08690: Hamilton Square, NJ

ZIP code 08690 is in Hamilton Square (64% of residents), Mercerville (9.4%) and White Horse (2.5%), in Mercer County, New Jersey. 24% of its residents live outside city limits. It is in New Jersey's 3rd congressional district. Its state senate district is State Senate District 14; its state house district is Assembly District 14.

19,470residents (2020 Census)
7.0 sq miland area
3cities and towns
1congressional district
24voting precincts

See it on the mapAll of New Jersey

City and county

City or townShare of ZIP residents
Hamilton Square64%
Mercerville9.4%
White Horse2.5%

CountyShare of ZIP residents
Mercer County100%

Town or county subdivisionShare of ZIP residents
Hamilton township98%
Robbinsville township2.4%

Congressional district

Congressional districtShare of ZIP residents
New Jersey's 3rd congressional district (NJ-03)100%

State legislative districts

State senate districtShare of ZIP residents
State Senate District 14100%

State house districtShare of ZIP residents
Assembly District 14100%

Voting precincts

24 voting precincts overlap ZIP 08690. Map them, with each precinct's share of the ZIP's residents.

Get this in your AI agent

Your agent can get these cities, counties, districts and precincts with their shares, and their GeoJSON boundaries, from Boundary Atlas. Add https://atlas-production-d344.up.railway.app/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:

related_geographies(id="us:zcta:08690")

ZIP 08690 here is the Census Bureau's ZIP Code Tabulation Area, which approximates the USPS ZIP Code; PO-box-only ZIPs have none. Districts are the maps in force for the November 3, 2026 election.