Carved from a large land grant named New Towne Hundred by an act of Maryland's early colonial government to advance commerce, Leonardtown was known at various times as Sheppard's Old Fields, Seymour Towne, Leonard Town, and finally Leonardtown. It became the county seat in 1708, and after a more aggressive group of commissioners was formed in 1728, the town was renamed and its growth was encouraged. During the Revolutionary War, an unarmed militia was stationed there, citizens elected representatives for the new United States government, and food and supplies for the Continental Army were stored there. Over the years, hotels and taverns lined the town square to serve residents conducting official business, while farm goods and tobacco were exported from the town wharf to regional and international markets, with water transportation by sloop, schooner, or steamship continuing until the end of the 1930s. During the War of 1812, British forces attacked Leonardtown on July 19, 1814, when an estimated 1,500 British Royal Marines divided into three companies, two marching to town and a third arriving at the wharf in Admiral Cockburn's barges; along the way private homes were raided, and in Leonardtown the British found supplies of the 30th Regiment and 40 stands of arms that had been destroyed, along with tobacco, flour, provisions, and other articles, which Rear Admiral George Cockburn reported were taken without accident. The first courthouse was a private residence owned first by Steven Murty and then Thomas Cooper, legislation authorized funds for a wooden courthouse by 1710, a brick courthouse built in 1736 stood until a fire destroyed it and all county records dating up to 1831, and the present courthouse was built around 1901. For many years the courthouse served as the county's largest meeting place, and for three centuries residents have come there to vote, sign official documents, record financial transactions, and take part in legal challenges.