Savannah is Georgia's oldest city; it was founded by James Oglethorpe in 1733 and served as the colonial seat of government. During the American Revolution the British took Savannah on Dec. 29, 1778, and held it until July, 1782. A land-sea force of French and Americans tried to retake the city in 1779, first by siege and then by direct assault (on Oct. 9), but failed dismally. Savannah was the state capital from 1782 to 1785. With the growth of trade, and especially after the invention of the cotton gin and the construction of railroads extending to the cotton fields of central Georgia, the city became a rival of Charleston as a commercial center. The first steamship to cross the Atlantic, the Savannah, sailed from there to Liverpool in 1819. In the Civil War, Fort Pulaski, on an island near the mouth of the Savannah River, was captured by Federals in 1862, but the city did not fall until Dec. 21, 1864, when Sherman entered.