Hattiesburg, city (1990 pop. 41,882), seat of Forrest co., SE Miss., on the Leaf River; inc. 1884. It is the rail, trade, and industrial center of a farm and timber area. Once a great lumbering city, Hattiesburg now produces sand and gravel, steel, lumber, industrial machinery, signs, resins, furniture, apparel, rubber, food and beverages, and chemicals. It is the seat of the Univ. of Southern Mississippi and of William Carey College. De Soto National Forest is in the area.