​DECATUR, a flourishing city of the United States, capital of Macon county, Illinois, situated in the midst of a rich agricultural district to the right of the Sangamon river,- at a railway junction about 38 miles east of Spring field. It is well built, and has 15 churches and 24 public schools ; but none of its edifices are individually remarkable. Among its industrial establishments is a large rolling mill. Population in 1870, 7161.