Illinois State Route 47 is a long, rural north-south state road that runs from Wisconsin State Route 120 south of Lake Geneva, WI and by Hebron, IL to near Seymour at Illinois State Route 10, just south of Interstate 72. This is a distance of about 160 miles (257 km).
The IllinoisStateRoute system (typically abbreviated as ILL) was formed in 1918, and each road was numbered in chronological order.
Thus, it is not uncommon to find groups of routes with similar numbers around each other (routes 23, 26, and 29 are found in north-central Illinois, while routes 56, 58, 59, 60, 62, 64, 68 and 72 can all be found in northern Chicagoland).
Route 1 was formed as the primary highway, stretching well over 350 miles from Chicago to the Wabash River near Kentucky as part of the Dixie Highway.