[2] When the district was first established, the district represented parts of the Northwest side of Chicago and the northern suburbs of Cook County, and the western suburbs of Cook County.
[3] New boundaries were adopted in August 2001, with redistricting taking place following the 2000 United States Census.
[4] In regards to townships and equivalent jurisdictions, the district's redistricted boundaries included portions of the city of Chicago and portions of the Leyden, Maine, Norwood Park, Oak Park, and River Forest townships.
[12] Its redistricting was seen as having made the district's voter demography more Republican-leaning than it had previously been.
[2] The overall boundaries of the district are similar to the previous ones, containing portions of the cities of Chicago, River Forest, Elmwood Park, River Grove, Rosemont, Harwood Heights, Norridge, Park Ridge, Niles, Glenview, Des Plaines, Mount Prospect, Arlington Heights, Prospect Heights, Rolling Meadows, and an unpopulated portion of Melrose Park.