The Secret Service
The United States Secret Service, established in 1865 to safeguard the nation's currency, is best known as the agency responsible for protecting the president, a duty it assumed in 1901 after the assassination of William McKinley. Secret Service agents’ courage, creativity, and dedication are taxed to the utmost in safeguarding the president.
The special agents and uniformed officers' ever-expanding role now includes protecting the president, the president’s family, presidential candidates, and former presidents and guarding executive offices and diplomatic missions.
After John Kennedy's death in 1963, the agency increased the number of agents detailed to the president, employed new communications technology, and became more proactive in intelligence gathering.