Can you name the Union Army officer who fought at Gettysburg and later became president after the Civil War? No, it wasn't Grant. Nor was it Rutherford B. Hayes, James A. Garfield, Benjamin Harrison, or William McKinley. Each of these men fought in the Union army during the Civil War and each became president later on. Grant was Commanding General of the Union Army. Hayes served in the 23rd Ohio Infantry. Garfield was commissioned as a colonel in the 42nd Ohio Infantry. Harrison helped raise the 70th Indiana Infantry and served as a brigadier general. McKinley served as a commissary sergeant and delivered rations under fire at Antietam. But none of them was at Gettysburg.
The answer to my question is none other than Union colonel Emil Johann Rudolph Frey of the 82nd Illinois Infantry Regiment. (Yes, this was a trick question!)
Frey was taken prisoner on the first day of the battle of Gettysburg and held in Libby Prison for 18 months before being exchanged. Frey was born in Basel, Switzerland in 1838. In 1860 he emigrated to the United States and a year later enlisted in the Union army as a private. He held the rank of major at the end of the war. After the Civil War, Frey returned to his native Switzerland and was elected to the Swiss National Council. From 1882-1888, he served as the first ambassador to the United States in Washington, DC. Frey was confirmed as president of the Swiss Federation in 1894. He died on Christmas Eve, 1922.
So there you have it -- another one of the great surprises of the Civil War!