Pinkerton with Abraham Lincoln.
Allan Pinkerton (1819-1884) was a U.S. detective. He was born in Glasgow, Scotland on August 25, 1819 and emigrated to U.S. in 1842. In Chicago, Illinois in 1852, he formed the first detective agency, Pinkerton Agency, which solved a series of train robberies. He was head of US Secret Service in 1861-1862 and foiled an assassination plot in Baltimore, Maryland, while guarding Abraham Lincoln on his way to his inauguration for his first term as president of the U.S.

He died in Chicago, Illinois, on July 1, 1884.

See American Civil War spies