President Abe Lincoln formed the Secret Service on the same day that he was assassinated

With a reported one-third of the currency in circulation being counterfeit at the time, the Secret Service was created on July 5, 1865, in Washington, D.C. to suppress counterfeit currency. Chief William P. Wood was sworn in by Secretary of the Treasury Hugh McCulloch. It was commissioned in Washington, D.C. as the “Secret Service Division” of the Department of the Treasury with the mission of suppressing counterfeiting.

Former USSS badge, used from 1875 to 1890.Source

The legislation creating the agency was on Abraham Lincoln’s desk the night he was assassinated. At the time, the only other federal law enforcement agencies were the United States Park Police, the U.S. Post Office Department’s Office of Instructions and Mail Depredations (now known as the United States Postal Inspection Service), and the U.S. Marshals Service.

The first photographic image of the new president. Source

The Marshals did not have the manpower to investigate all crime under federal jurisdiction, so the Secret Service began to investigate everything from murder to bank robbery to illegal gambling. After the assassination of PresidentWilliam McKinley in 1901, Congress informally requested that the Secret Service provide presidential protection. A year later, the Secret Service assumed full-time responsibility for presidential protection. In 1902, William Craig became the first Secret Service agent to die while serving, in a road accident while riding in the presidential carriage.

The Secret Service was the first U.S. domestic intelligence and counterintelligence agency. Domestic intelligence collection and counterintelligence responsibilities were vested in the Federal Bureau of Investigation (FBI) upon the FBI’s creation in 1908. The Secret Service assisted in arresting Japanese American leaders and in the Japanese American internment during World War II. Essentially all of the agency’s missions were later taken over by subsequent agencies such as the Federal Bureau of Investigation (FBI),Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), and Internal Revenue Service (IRS), until only its duties in protection and combatting financial crime remained.