 However, Wallace delayed Early for nearly a full day, buying enough time for Ulysses S. Grant to send reinforcements from the Army of the Potomac to the Washington defenses.Thousands of Union troops were stationed in Charles County, and the Federal Government established a large, unsheltered prison camp at Point Lookout at Maryland's southern tip in St. Mary's County between the Potomac River and the Chesapeake Bay, where thousands of Confederates were kept, often in harsh conditions.Of the 50,000 Southern soldiers held in the army prison camp, who were housed in tents at the Point between 1863 and 1865, according to the Maryland Department of Natural Resources, (Maryland Park Service) nearly 4,000 died, although this death rate of 8 percent was less than half the death rate among soldiers who were still fighting in the field with their own armies.