Ocmulgee Mounds National Historical Park (formerly Ocmulgee National Monument) in Macon, Georgia, United States preserves traces of over ten millennia of culture from the Native Americans in the Southeastern Woodlands. Its chief remains are major earthworks built before 1000 CE by the South Appalachian Mississippian culture (a regional variation of the Mississippian culture.) These include the Great Temple and other ceremonial mounds, a burial mound, and defensive trenches. They represented highly skilled engineering techniques and soil knowledge, and the organization of many laborers. The site has evidence of "12,000 years of continuous human habitation." The park is located on the east bank of the Ocmulgee River. Macon, Georgia developed around the site after the United States built Fort Benjamin Hawkins nearby in 1806 to support trading with Native Americans. For thousands of years, succeeding cultures of prehistoric indigenous peoples had settled on what is called the Macon Plateau at the Fall Line, where the rolling hills of the Piedmont met the Atlantic coastal plain. The monument designation included the Lamar Mounds and Village Site, located downriver about from Macon. The site was designated for federal protection by the National Park Service (NPS) in 1934, listed on the National Register of Historic Places in 1966, and redesignated in 2019 as a national historical park. National Historical Park While the mounds had been studied by some travelers, professional excavation under the evolving techniques of archeology did not begin until the 1930s, under the administration of President Franklin D. Roosevelt during the Great Depression. The Works Progress Administration (WPA) sponsored large-scale archaeological digs at the site between 1933 and 1942. Workers excavated portions of eight mounds, finding an array of significant archeological artifacts that revealed a wide trading network and complex, sophisticated culture. On June 14, 1934, the park was authorized by Congress as a national monument and formally established on December 23, 1936, under the National Park Service. As an historic unit of the Park Service, the national monument was listed on the National Register of Historic Places on October 15, 1966. The John D. Dingell, Jr. Conservation, Management, and Recreation Act, signed March 12, 2019, redesignated it as a national historical park and increased its size by about 2,100 acres. It has an NPS-owned area of . The expanded area will be conveyed to the Park Service following redevelopment. An additional 906 acres were transferred to the park on February 9,