Illinois's 16th congressional district

The 16th congressional district of Illinois is represented by Republican Darin LaHood. Prominent past representatives from the 16th district have included Everett Dirksen, who went on to become the Republican leader in the United States Senate; John B. Anderson, who became the 3rd highest ranking Republican in the House and went on to run as a major independent candidate in the 1980 Presidential election; and Lynn Martin, who later served as United States Secretary of Labor.

For more than six decades, the shape of the 16th district fluctuated far less than that of any other Illinois congressional district. At this time, it generally included the northwest corner of the state, extending just far enough to the east to grab its largest city, Rockford. By the 1990s, it also extended eastward to include part of McHenry County, an outer suburb of Chicago. This geographic stability also contributed to electoral stability. It first became a Rockford-based district for the 1948 election, and from then until 2012, it was represented by just five people, all but one of whom was a Republican. The sole Democrat to have held it in that period, John W. Cox, Jr., only did so for one term.