The United States Marines and the United States Secret Service were responsible for the security for the President of the United States. Prior to the United States entrance into the war, Franklin Delano Roosevelt (FDR) frequently cruised along the waterways, on the Presidential yacht the USS Potomac. He also visited his home in Hyde Park, New York and his retreat in Warm Springs, Georgia. As German U-Boat activity increased along the Atlantic coast, the Secret Service became concerned for the President's safety. FDR's physician recommended a retreat that would not interfere with his health conditions of asthma, and polio. It was critical that the President remain close to the Nation's Capital during this national crisis. National Park Service Director Newton Drury was given the task to locate a site for the President to use as a retreat within 50 to 90 miles of Washington, D.C. Drury turned the assignment over to Conrad Wirth, his assistant in charge of recreation and land use planning. The group chose Camp #3, Hi-Catoctin. Camp Hi-Catoctin had been used as a summer camp for federal employees as well as Boy Scout groups. Two-thirds of this camp was currently in use by the Office of Strategic Services (OSS). Drury accompanied the President to Catoctin for the first time on April 22, 1942. According to Drury, he was "very much pleased with the area" and asked them to "proceed immediately with plans and estimates." Final approval for the project was given on April 30, 1942. When Franklin Roosevelt looked at the spectacular view from his new mountain retreat he said that "this is Shangri-La."
Roosevelt's first day-long visit was on July 5, 1942, and he entertained the first guests on July 18-21, 1942. Throughout the war, Roosevelt had a number of important visitors at his mountain retreat. They included OSS director William Donovan, OSS instructor William Fairbairn, Supreme Justice William O. Douglas, Princess Martha of Norway, and Princess Juliana of the Netherlands. The most memorable visitor to the Catoctin Recreational Demonstration Area and the residents of Thurmont was British Prime Minister Winston Churchill.
The existence of the Presidential Retreat was a secret. However, Thurmont residents generally knew when the President was in town. Marines would line the roads and bridges and the President was seen traveling through Thurmont in a special limousine escorted by state police. FDR had use of the only armored car in the United States. The FBI had seized the vehicle from gangster Al Capone for tax evasion in 1932.
The camp was not used during the winter months and would remain closed from December to May. The President made 19 visits to his retreat during the summers of 1942 and 1943. Roosevelt spent a total of 64 days at Shangri-La during World War II.
The state of Maryland eventually received only half of the Catoctin Recreational Demonstration area as promised under the original Federal Recreational Demonstration Area program. The northern half remained a unit of the National Park Service at the request of Harry Truman in 1952, in order to maintain a buffer around the Presidential Retreat.