The United States Secret Service was created in 1865 as a wing of the US Treasury Department with a mission to get counterfeit currency under control. It is estimated that after the Civil War, up to 50% of the nation’s currency was counterfeit. Obviously that would have a drastic effect on the economy and inflation.

Counterfeiting was so wide spread that the identities of the original agents had to be kept secret to avoid tipping off the bad guys. Hence the “Secret” part.

The agency pre-dates all other federal law enforcement agencies. Originally the mission was strictly related to counterfeit currency, though it was quickly expanded to include many other infractions of federal law such as bootlegging, smuggling, and mail robbing. As the Federal Government grew, more agencies (like the FBI and ATF) were created and responsibilities shifted.

The Secret Service did not get into the Presidential Protection business until the turn of the century. Early Americans bent over backwards to avoid having their President looking like a King, and protection was one of those things that felt King-like. The President was supposed to be a man of the people.

It wasn’t until the 3rd Presidential assassination in 35 years (Lincoln 1865, Garfield 1881, and McKinley 1901) that the idea of Presidential protection really caught on.

In 1901 congress asked for protection of Theodore Roosevelt (McKinley’s successor) but the request was informal and temporary. From 1906 – 1950 the authorization to provide protection needed to be renewed annually.

After Harry Truman was attacked in 1950 (I wrote about it in this post, which a crazy Puerto Rican guy commented on when I wasn’t looking) congress finally made the protection permanent. As an aside, before his attack, Truman would routinely take strolls down Pennsylvania Avenue without any guards. My how times have changed.

As time went on protection was extended to the President’s family, the VP, former Presidents, President-Elects, and after the RFK assanation, certain presidential candidates. Some visiting foreign dignitaries qualify for protection as well.

In 2003, the Secret Service became part of the Department of Homeland Security, rather than the Treasury. Despite this, they do retain the responsibility of investigating counterfeit currency in addition to protection.

Source: National Geographic Channel and The USSS web site.