* Occupation: United States Army general
* Birth Date: September 20, 1820
* Death Date: July 1, 1863
* Place of Birth: Lancaster, Pennsylvania
* Place of Death: Gettysburg, Pennsylvania
Background:
- Graduated from the United States Military Academy in 1841
- Served in the Mexican-American War and was brevetted captain for gallantry at Monterrey
- Fought in the Seminole Wars in Florida
Role at the Battle of Gettysburg:
- Commanded the I Corps of the Army of the Potomac
- Ordered his troops to march to Gettysburg after receiving reports of Confederate activity in the area
- Engaged the Confederates in what is considered the beginning of the Battle of Gettysburg
- Was killed in action on July 1, 1863, near McPherson's Woods