The
United States Secret Service is a federal law enforcement agency under the Department of Homeland Security charged with conducting criminal investigations and protecting U.S. political leaders, their families, and visiting heads of state or government. Until 2003, the Secret Service was part of the Department of the Treasury, as the agency was founded in 1865 to combat the then-widespread counterfeiting of U.S. currency. President Abraham Lincoln signed the legislation on April 14, 1865, just a few hours before he was assassinated. In 1901, the Secret Service was also assigned to presidential protection duties.