The Metropolitan Police replaced previous law enforcement organizations. Before the formation of the District in 1801, county constables had jurisdiction over the area, along with the comparatively developed police force for the City of Alexandria. Within the City of Washington, the first police superintendent was named in 1803, and the city divided into four policing wards, each under a constable, in 1804. Yet another force, the 16-member Auxiliary Guard of the City of Washington, was established by Act of Congress in August 1842, purportedly because President John Tyler had been burned in effigy, and had rocks thrown at him on the White House grounds. The formation of the Metropolitan Police dissolved all these previous authorities. (The Militia of the District of Columbia was created in the Assumption Act of May 3, 1802, active as peacekeepers within the District but tasked with defending the federal government, and commanded directly by the President as a military force, not law enforcement.)