On July 5, 1865, the United States Secret Service began operating under the Treasury Department. From the article:
"The United States Secret Service is one of the oldest federal law enforcement agencies in the country and ranks among the most elite in the world. With its origin dating back to the end of the American Civil War, the Secret Service was originally founded to combat the then-widespread counterfeiting of U.S. currency. In 1901, the agency was asked to begin its protective mission after the assassination of President William McKinley – the third sitting U.S. President to be assassinated. Today, the Secret Service proudly continues to protect both national leaders and visiting foreign dignitaries while helping to secure the nation’s financial infrastructure through financial and cybercrime investigations.
The men and women who make up the Secret Service – both past and present – have embodied a tradition of excellence through integrity, commitment and honor. Their stories are the Secret Service’s history – a proud history that continues to evolve and grow with every passing year."