Who commanded the Union XI Corps at Gettysburg?

Oliver O. Howard commanded the Union XI Corps at Gettysburg.

Howard, a major general in the Army of the Potomac, led the Eleventh Corps during the battle's opening stages and remained its recognized commander throughout the engagement. The corps contained three divisions, commanded by Francis C. Barlow, Adolph von Steinwehr, and Carl Schurz.

On July 1, the XI Corps arrived north of Gettysburg and formed part of the Union line. Confederate attacks overwhelmed portions of the corps, forcing a retreat through the town to Cemetery Hill. Howard also helped organize the Union defensive position on the high ground south of town.

A temporary command shift can cause confusion: after Major General John F. Reynolds was killed, Howard briefly exercised overall command on the field, while Carl Schurz took operational command of the XI Corps for part of that afternoon. Nevertheless, Howard was the corps commander at Gettysburg and the standard answer to this question.