Decatur ( ) is the largest city and the county seat of Macon County in the U.S. state of Illinois, with a population of 70,522 as of the 2020 Census. The city was founded in 1829 and is situated along the Sangamon River and Lake Decatur in Central Illinois. Decatur is the seventeenth-most populous city in Illinois. The city is home of private Millikin University and public Richland Community College. Decatur has an economy based on industrial and agricultural commodity processing and production, including the North American headquarters of agricultural conglomerate Archer Daniels Midland, international agribusiness Tate & Lyle's largest corn-processing plant, and the designing and manufacturing facilities for Caterpillar Inc.'s wheel-tractor scrapers, compactors, large wheel loaders, mining class motor grader, off-highway trucks, and large mining trucks. History The city is named after War of 1812 naval hero Stephen Decatur. Decatur is an affiliate of the U.S. Main Street program, in conjunction with the National Trust for Historic Preservation. The Potawatomi Trail of Death passed through here in 1838. Post No. 1 of the Grand Army of the Republic was founded by Civil War veterans in Decatur on April 6, 1866. The Edward P. Irving House, designed by Frank Lloyd Wright and built in 1911, is located at No. 2 Millikin Place, Decatur. In addition, the Robert Mueller Residence, 1 Millikin Place, and the Adolph Mueller Residence, 4 Millikin Place, have been attributed to Wright's assistants Hermann V. von Holst and Marion Mahony. Abraham Lincoln Decatur was the first home in Illinois of Abraham Lincoln, who settled just west of Decatur with his family in 1830. At the age of 21, Lincoln gave his first political speech in Decatur about the importance of Sangamon River navigation that caught the attention of Illinois political leaders. As a lawyer on the 8th Judicial Circuit, Lincoln made frequent stops in Decatur, and argued five cases in the log courthouse that stood on the corner of Main & Main Streets. The original courthouse is now on the grounds of the Macon County Historical Museum on North Fork Road. John Hanks, first cousin of Abraham Lincoln, lived in Decatur. On May 9 and 10, 1860, the Illinois Republican State Convention was held in Decatur. At this convention Lincoln received his first endorsement for President of the United States as "The Railsplitter Candidate". In commemoration of Lincoln's bicentennial, the Illinois Republican State Convention was held in