Marietta, city, seat of Cobb County, northwestern Georgia, near Atlanta; established 1834, incorporated 1852. Marietta is the center for a major aircraft industry. The city is the site of the Southern College of Technology (1948) and Life Chiropractic College (1974). Kennesaw College (1966), Dobbins Air Force Base, and Kennesaw Mountain National Battlefield Park, the scene of a major American Civil War battle (1864) in which Union forces were defeated, are in the area. Many Union and Confederate soldiers are buried in Marietta. Population 30,829 (1980); 44,129 (1990); 58,748 (2000).