May 10 (UPI) -- On this date in history: In 1865, Confederate President Jefferson Davis was captured by Union troops. He spent the next two years in prison. In 1869, the "golden spike" was driven at Promontory, Utah, joining the Union Pacific and the Central Pacific lines to form America's first transcontinental railway. In 1908, Mother's Day was observed for the first time in the United States. In 1924, J. Edgar Hoover was appointed director of the FBI. He held the position until his death in