Onset, Massachusetts
Onset is a Census-designated place (an unincorporated community) in Plymouth County, Massachusetts, with 1,617 residents in 2020. It is in Massachusetts's 9th congressional district. Its state senate district is Third Bristol and Plymouth District; its state house district is 2nd Plymouth District.
County
| County | Share of residents |
|---|---|
| Plymouth County | 100% |
Congressional district
| Congressional district | Share of residents |
|---|---|
| Massachusetts's 9th congressional district (MA-09) | 100% |
Elected officials
| Office | Member | Contact | Share of residents |
|---|---|---|---|
| U.S. Representative (MA-09) | William R. Keating (D) | 202-225-3111 | 100% |
| U.S. Senator | Edward J. Markey (D) | 202-224-2742 · contact form | statewide |
| U.S. Senator | Elizabeth Warren (D) | 202-224-4543 · contact form | statewide |
| State Senator (Third Bristol and Plymouth District) | Kelly Dooner (R) | 100% | |
| State Representative (2nd Plymouth District) | John Gaskey (R) | 100% |
Officials serving now (members of Congress until January 3, 2027). Sources: State legislators: Open States (public domain); Members of Congress: the @unitedstates project, congress-legislators (CC0).
Local government
- Onset laws: search for the Onset, Massachusetts code of ordinances
- Plymouth County laws: search for the Plymouth County, Massachusetts code of ordinances
State legislative districts
| State senate district | Share of residents |
|---|---|
| Third Bristol and Plymouth District | 100% |
| State house district | Share of residents |
|---|---|
| 2nd Plymouth District | 100% |
ZIP codes
Percentages mark ZIPs only partly in Onset: the share of that ZIP's residents living in it.
Get this in your AI agent
Your agent can get Onset's counties and districts with shares, its ZIP codes (level='zcta'), and its boundary as GeoJSON (get_boundaries). Add https://boundarymcp.com/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:
related_geographies(id="us:place:2551160")
Onset here is the Census Bureau's place boundary as of January 1, 2025 (a Census-designated place, which has no municipal government). Shares are of 2020 Census population. Districts are the maps in force for the November 3, 2026 election.