William H. Crook (1839–1915) served in the Union Army during the Civil War, and then joined the Washington Police Force, before he was hired away to become one of President Abraham Lincoln’s bodyguards. He was not on duty the night of Lincoln’s assassination, but continued on the job for Lincoln’s successor, Andrew Johnson. When Ulysses Grant became president, he appointed Crook “Executive Clerk of the President of the United States” and then “Chief Disbursing Officer.” He held that title until retiring, in 1915, having served presidents for 50 years.