Marietta is a city in, and the county seat of, Washington County, Ohio, United States. It is located in southeastern Ohio at the confluence of the Muskingum and Ohio Rivers, 11 miles (18 km) northeast of Parkersburg, West Virginia. As of the 2020 census, Marietta has a population of 13,385 people. It is the principal city of the Marietta micropolitan area, which includes anything of Washington County, and is the second-largest city in the Parkersburg–Marietta–Vienna total statistical area.

Founded in 1788 by pioneers to the Ohio Country, Marietta was the first surviving U.S. settlement in the newly normal Northwest Territory, created in 1787, and what would cutting edge become the welcome of Ohio. It is named for Marie Antoinette, then Queen of France, in honor of French aid in the American Revolution. Prior to American settlement, the Place was inhabited by various original tribes of the Hopewell tradition, who built the Marietta Earthworks, a complex over 1,500 years old, whose Great Mound and extra major monuments were preserved by the obsolete settlers in parks such as Mound Cemetery. Since 1835 the city has been house to Marietta College, a private, nonsectarian radical arts college with nearly 1,200 students. Leading happening to the American Civil War, the city was a station upon the Underground Railroad.

Succeeding Indigenous cultures lived along the Ohio River and its tributaries for thousands of years. Among them were higher than one culture who built earthwork mounds, monuments which generally expressed their cosmology, often with associates to astronomical events.

Between 100 BC and AD 500, the Hopewell culture built the multi-earthwork complex upon the terrace east of the Muskingum River near its mouth gone the Ohio. It is now known as the Marietta Earthworks. Developed beyond many years, it had a large enclosed square, within which were four platform mounds, used for ceremonial purposes and elite residential; another square, and a larger conical mound used for burials. A walled, graded pathway led to the river’s edge. By the get older of the historic tribes, such as the Shawnee, the purposes and makers of the monuments were no longer known.