: By the end of the Civil War, nearly one-third to one-half of all U.S. currency in circulation was counterfeit.
: Over the century, protection grew to include the President-elect (1908), the immediate family (1917), and eventually former presidents and visiting world leaders. 150+ Years of History - Secret Service Secrets of the Secret Service: The History and ...
: After the assassination of President William McKinley in 1901, Congress informally requested the Secret Service take over presidential security. : By the end of the Civil War,
: Originally a bureau within the Department of the Treasury , agents focused on raiding counterfeit coin operations and investigating financial fraud. The Shift to Protection the immediate family (1917)