La Plata lies on the prairie of northeastern Missouri. On March 17, 1827, Drury Davis established his trading post a half-mile from present-day La Plata. The town eventually developed at the intersection of north-south and east-west stage coach roads. In 1855, Henry O. Clark surveyed the town and presented the plats to three settlers, Louis Gex, Theodore Saunders and Dr. W.W. Moore; they named three of the principal streets for themselves.