Seymour is a city in Jackson County, Indiana, United States. The population was 17,503 at the 2010 census. Indiana is referred to as the "Crossroads of America." Seymour holds particular significance due to the north/south and east/west railroads intersecting downtown.
The north/south line (the Jeffersonville, Madison and Indianapolis Railroad) was built in the 1840s and connected Indianapolis to the Ohio River at Jeffersonville. In 1852, Capt. Meedy Shields persuaded John Seymour into building the east/west railroad (the Ohio and Mississippi Railroad) through his land. In return, Shields named the area Seymour.
Aisin USA and Rose Acre Farms have their headquarters in Seymour, and Cummins has a plant in Seymour. The city is also the home of the third largest high school gym in the United States.
Seymour is the birthplace of singer John Mellencamp.