Mount Calvert overlooks the confluence of the Patuxent River and the Western Branch and preserves archaeological and historical evidence of three cultures that lived there: American Indian, European-American, and African-American. Since 1996, archaeologists have recovered thousands of artifacts left by Mount Calvert's inhabitants over the centuries, piecing together glimpses of life there spanning 8,000 years. Archaeological evidence shows that American Indians were present from the Archaic Period (7500-1000 BC) through the Woodland Period (1000 BC-1600 AD), with early Archaic hunters and gatherers visiting the upper Patuxent to harvest the river's resources and later Woodland farmers living in permanent villages along the river. Beginning in the 1680s, the Maryland General Assembly created towns in the Chesapeake Bay region to encourage settlement, and in 1684 Mount Calvert became a town site. When Prince George's County was established in 1696, Mount Calvert was renamed Charles Town and designated as the county seat, before the county seat moved to Upper Marlboro in 1721. Between the 1780s and 1860s, Mount Calvert was a tobacco plantation dependent upon slave labor; the brick plantation house was built in the 1780s, it was owned over the years by the John Brown, John Brookes, and Samuel Berry families, and by the mid-1800s, 51 enslaved African Americans lived and worked at Mount Calvert plantation.