Centerville is a city in and the county seat of Appanoose County, Iowa, United States. The population was 5,412 in the 2020 census, a decline from 5,924 in 2000. After the turn of the 20th century Centerville's coal mining industry attracted European immigrants from Sweden, Italy, Croatia, and Albania. Centerville is also home of the largest town square in the state of Iowa. History Founded in 1846 by Jonathon Stratton under the name of "Chaldea," the city was planned around a unique two-block long city square. The name was later changed to Senterville, named after William Tandy Senter, a prominent Tennessee politician. When incorporation papers were filed in 1855, someone mistook the name for a misspelling and corrected it to Centerville. A mining town The first coal mine in Centerville was opened in 1868, with its mine shaft about one-half mile from the Chicago, Burlington and Quincy Railroad depot. Horse-power was used to raise coal from the mines until 1872, when the Watson Coal Company opened a mine equipped with a steam hoist. The Centerville Block Coal Company, organized in 1894, consolidated the operation of numerous mines in the region to become the dominant mining company. In 1914, Centerville Block Coal produced over 100,000 tons of coal, ranking among the top 24 coal producers in the state. Centerville Block's largest competitor, formed around the same time, was the Scandinavian Coal Company, organized by a group of Swedish immigrants. By 1938, coal production in the Centerville region was 600,000 tons per year. The mines were in the Mystic coal bed, 125 feet below ground in Centerville but exposed at the surface in Mystic, 5 miles to the northwest. Centerville Block Coal's Relay Mine Number 3 was located on the west side of town (Number 31 on the map). By 1908, the coal face was a mile from the base of the shaft. Mules were used to haul trains of loaded coal tubs to the main haulage way, where they were hauled by a continuous loop of cable the last half mile to the shaft. The coal seam here was about 3 feet thick, and the shaft was 107 feet deep. A centrifugal blower 12 feet in diameter provided ventilation, and compressed air was used to power mining machinery. Local Assembly 1020 of the Knights of Labor was based in Centerville and had a membership of 150 in 1884. On April 1,