In 1843, several settlers were living in what is now Marion County. In the spring of 1845, a movement was made to secure a separate county organization. A meeting composed of the more prominent citizens living in the county was held at Lake Prairie. Lake Prairie was on the north bank of the Des Moines River, which is now Lake Prairie Township.
Among the important decisions to be made: to propose a name for the county; to recommend a person to act as organizing sheriff; to select a slate of county officers, to be voted on; and perhaps most important, to choose a location for the county seat. Many suggestions were made as to the name for the county. A Mr. Bainbridge denounced the names honoring foreigners and Indian chiefs and proposed the use of the name Marion, the name of a distinguished patriot of the War of Independence, Francis Marion. The motion was seconded and accepted by unanimous vote. Thus the proposal to organize the County of Marion was drawn up and approved by the General Assembly on June 10, 1845.
Three commissioners were appointed to establish the seat of government. On August 25, 1845 two of the commissioners, a Mr. Robinson and a Mr. Montgomery, made a report in favor of locating the county seat, on a high level prairie, about one mile south of the exact center of the county. They also suggested to local authorities that it be called Knoxville in honor of General Knox, another distinguished soldier in the American Revolution.
The first Marion County courthouse was built in 1846. It remained in use for about twelve years during which time it was also used for a school and religious services. A new courthouse was completed in 1858 and stood in the middle of the public square. It was regarded as one of the best in the state, and it served the county for nearly forty years. A special election was held on May 14, 1895 for the erection of a new courthouse at a cost not to exceed $80,000. It was completed and accepted by the Board of Supervisors on December 30, 1896.
If the surveying had been more strictly or accurately done, Marion County would be 24 miles square containing 576 square miles, but it is actually larger. Marion County's population in 1860 was 16,813; in 1900 it was 24,159; in 1950 it was 25,930; and in 1990 it was 30,001.
Thanks to Winona Davis for this information.
Population totals are from the State Historical Library resources personnel.