See below:

The father of Douglas MacArthur and Arthur MacArthur III, he was born in Massachusetts on June 2, 1845. At the outbreak of the Civil War, he was living in Wisconsin and immediately joined the 24th Wisconsin Volunteer Infantry, seeing action at Chickamauga, Stones River, Chattanooga, the Atlanta Campaign and Franklin. He was awarded the Medal of Honor (in 1890) for service at Missionary Ridge, and he and his son, Douglas, are one of only two father-son recipients of the Medal of Honor in U.S. history (the others being Theodore Roosevelt, who was recently awarded the Medal of Honor for his exploits in the Spanish-American War, and his son, Theodore Roosevelt, Jr., who was awarded the Medal of Honor for his actions in World War II).
He left the Army in June 1865 and began the study of law, but it was not for him and he returned to his first love, the Army, in February 1866, receiving a commission as a Second Lieutenant in the Regular Army.

Link: http://www.arlingtoncemetery.net/amacart.htm

Seems McArthur is out of the runnung as boy general. Stan