John Buford

John Buford, Jr. (March 4, 1826 – December 16, 1863) was a United States Army cavalry officer. He fought for the Union as a brigadier general during the American Civil War. Buford is best known for having played a major role in the first day of the Battle of Gettysburg on July 1, 1863, by identifying, taking, and holding the "high ground" while in command of a division.
Buford rendered valuable service to the Army, both in the pursuit of Robert E. Lee after the Battle of Gettysburg, and in the Bristoe Campaign that autumn, but his health started to fail, possibly from typhoid. Just before his death at age 37, he received a personal message from President Abraham Lincoln, promoting him to major general of volunteers in recognition of his tactical skill and leadership displayed on the first day of Gettysburg.
https://en.wikipedia.org/wiki/John_Buford