Upper Marlboro, officially the Town of Upper Marlboro, is the seat of Prince George's County, Maryland, United States. The population within the town limits was 631 at the 2010 U.S. Census, although Greater Upper Marlboro is many times larger.
Upper Marlboro was established in 1706 as "Marlborough Town", after John Churchill, 1st Duke of Marlborough. In 1744, the town was renamed to "Upper Marlborough". In the late 19th century, the town's name changed from Upper Marlborough to Upper Marlboro. The name change is linked to a postal clerk who felt that the last three letters, "ugh", did not properly fit on the rubber stamps being used at the time. By 1893, postal guides were referring to the town as Upper Marlboro and the name stuck, despite a proposed ballot to have it changed back in 1968.
The area of Upper Marlboro was first settled around 1695. It was named after John Churchill, 1st Duke of Marlborough, an ancestor of Winston Churchill. The land, which was to become the town, was part of several estates known as Grove Landing, Meadows, and Darnall's Chance, owned by the Brooke, Beall, and Darnall families, respectively.