"The U.S. Secret Service has two missions--criminal investigations and protection. Criminal investigation activities have expanded since the inception of the Service from a small anti-counterfeiting operation at the end of the Civil War, to now encompassing financial crimes, identity theft, counterfeiting, computer fraud, and computer-based attacks on the nation's financial, banking, and telecommunications infrastructure, among other areas. Protection activities, which have expanded and evolved since the 1890s, include ensuring the safety and security of the President, Vice President, their families, and other identified individuals and locations. In March 2003, the U.S. Secret Service was transferred from the Department of the Treasury to the Department of Homeland Security. Prior to enactment of the Homeland Security Act of 2002 (P.L. 107-296), the U.S. Secret Service had been part of the Treasury Department for over 100 years. Since the September 2001 terrorist attacks, there have been consistent and continuing questions concerning the U.S. Secret Service. Are the two missions of the Service compatible and how should they be prioritized? Is the Department of Homeland Security the most appropriate organizational and administrative location for the Secret Service? These, and other policy issues such as the Secret Service's role in securing presidential inaugurations, have been raised and addressed at different times by Congress and various administrations during the long history of the Service."
CRS Report for Congress, RL34603