Response review

I'll look that up for you.
Your U.S. representative in Illinois's 12th congressional district is **Mike Bost (R)**.


Illinois' 12th Congressional District in the United States House of Representatives is represented by Mike Bost (R).
 
The 12th congressional district of Illinois is a congressional district in the southern part of the U.S. state of Illinois, and it has been represented by Republican Mike Bost since 2015.


A bit more context: 
With a Cook Partisan Voting Index of R+22, it is the most Republican district in Illinois.
 
The district covers parts of Madison and St. Clair counties, and all of Alexander, Franklin, Hamilton, Jackson, Jefferson, Monroe, Perry, Pulaski, Randolph, Union and Williamson counties.


If you'd like, I can help you find his office contact information or verify your specific address falls within IL-12.