United States Secret Service

The United States Secret Service operates as a dual-purpose federal agency, handling both criminal investigations and high-stakes protective details. While its origins lie in the Treasury Department's fight against currency counterfeiting, the organization shifted its primary focus to security after the assassination of President William McKinley in 1901. Today, it stands under the Department of Homeland Security, tasked with safeguarding American political leaders, their families, and visiting heads of state.[edit]