Knoxville is a city in Marion County, Iowa, United States. The population was 7,731 at the 2000 census. It is the county seat of Marion County. Knoxville is home of the National Sprint Car Hall of Fame & Museum located next to the famous dirt track known as Knoxville Raceway.
The site for the future county seat of Marion County was selected because it was within a mile of the geographic center of the county, reasonably level and near a good source of timber. The first town lots were sold in 1845, and the town was named after General Knox to commemorate his service in the American Revolutionary War.
In early 1853, the citizens of Marion County created a committee to attract railroad development to the county and to Knoxville, with members promising to buy shares in any railroad that reached town. The first contender was the Muscatine, Oskaloosa & Council Bluffs, proposing an east-west line that would pass through Knoxville. By 1875, when this line reached Knoxville, it was the Chicago, Burlington & Quincy Railroad. The second railroad to reach Knoxville was the Chicago, Rock Island & Pacific, which completed a line from Oskaloosa in 1876.