Thomas Crittenden [US] reaches Lee and Gordon Mill on the Chickamauga River. Rosecrans [US] orders the rest of his men, spread out along 50 miles of Georgia's backwoods, to concentrate at this landmark.
Sterling Price, with 18,000 men, lays siege to Lexington, Missouri, with a federal force of 3.600 under Colonel James Mulligan. After fighting intensified on September 19, Mulligan surrendered on the 20th.