Members of the Counter Assault Division of the US Secret Service keep an eye on the crowd as President Barack Obama departs the Annual Legislative Conference of the United States Hispanic Chamber of Commerce in Washington, DC.-- Photo by Brook Kraft / Corbis for TIME
The United States Secret Service, one of the nation's oldest federal investigative law enforcement agencies, was founded in 1865 as a branch of the U.S. Treasury Department. It was originally created to combat the counterfeiting of U.S. currency - a serious problem at the time. In fact, following the Civil War, it was estimated that one-third to one-half of the currency in circulation was counterfeit.
In 1901, following the assassination of President William McKinley in Buffalo, New York, the Secret Service was first tasked with its second mission: the protection of the president. Today, the Secret Service's mission is two-fold: protection of the president, vice president and others; and investigations into crimes against the financial infrastructure of the United States.
Learn about protecting the President & Vice President, former U.S. Presidents, visiting foreign dignitaries and other protectees. -- USSS Protective Mission
U.S. assassination attempt statistics from Assassination in the United States: An Operational Study of Recent Assassins, Attackers, and Near Lethal Approaches (5.7M PDF)