Seneca, Illinois
Seneca is a village in LaSalle County (100% of residents) and Grundy County (0.3%), Illinois, with 2,314 residents in 2020. It spans 2 congressional districts: IL-14 (96%) and IL-16 (4.5%). It spans 2 state senate and 2 state house districts.
County
| County | Share of residents |
|---|---|
| LaSalle County | 100% |
| Grundy County | 0.3% |
Congressional districts
| Congressional district | Share of residents |
|---|---|
| Illinois's 14th congressional district (IL-14) | 96% |
| Illinois's 16th congressional district (IL-16) | 4.5% |
Elected officials
| Office | Member | Contact | Share of residents |
|---|---|---|---|
| U.S. Representative (IL-14) | Lauren Underwood (D) | 202-225-2976 | 96% |
| U.S. Representative (IL-16) | Darin LaHood (R) | 202-225-6201 | 4.5% |
| U.S. Senator | Richard J. Durbin (D) | 202-224-2152 · contact form | statewide |
| U.S. Senator | Tammy Duckworth (D) | 202-224-2854 · contact form | statewide |
| State Senator (State Senate District 38) | Sue Rezin (R) | 815-220-8720 | 52% |
| State Senator (State Senate District 53) | Chris Balkema (R) | 815-844-9179 | 48% |
| State Representative (State House District 75) | Jed Davis (R) | 331-867-8200 | 52% |
| State Representative (State House District 106) | Jason Bunting (R) | 779-218-3070 | 48% |
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
- Seneca laws: search for the Seneca, Illinois code of ordinances
- LaSalle County website: https://lasallecountyil.gov/
- LaSalle County laws: search for the LaSalle County, Illinois code of ordinances
- Grundy County website: http://www.grundyco.org
- Grundy County laws: search for the Grundy County, Illinois code of ordinances
State legislative districts
| State senate district | Share of residents |
|---|---|
| State Senate District 38 | 52% |
| State Senate District 53 | 48% |
| State house district | Share of residents |
|---|---|
| State House District 75 | 52% |
| State House District 106 | 48% |
ZIP codes
Percentages mark ZIPs only partly in Seneca: the share of that ZIP's residents living in it.
Get this in your AI agent
Your agent can get Seneca'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:1768640")
Seneca here is the Census Bureau's place boundary as of January 1, 2025. Shares are of 2020 Census population. Districts are the maps in force for the November 3, 2026 election.