One does not win the Medal of Honor, it is awarded. In the case of Arthur MacArthur, Jr., it was awarded on 30 June 1890. There are only two pairs of father-son recipients of the Medal of Honor, MacArthur and son, and Roosevelt and son.
CITATION:Rank and organization: First Lieutenant, and Adjutant, 24th Wisconsin Infantry. Place and date: At Missionary Ridge, Tenn., 25 November 1863. Entered service at: Milwaukee, Wis. Birth: Springfield, Mass. Date of issue: 30 June 1890. Citation: Seized the colors of his regiment at a critical moment and planted them on the captured works on the crest of Missionary Ridge.
[cr] a full colonel by the age of 19 (1864),
"When the war ended I was Lieutenant Colonel, but held the Governor's commission as Colonel, which the War Department refused to recognize." (From a letter of Arthur MacArthur, Jr. to Charles T. Clark of May 13, 1895)
I've read somewhere that this was a very sore point with the elder MacArthur until the day he died. There was some sort of sordid little backstory to this, of the "he done him wrong" nature, about someone's personal vendetta or something like that.
Thank you. I was alluding to the story told by Douglas MacArthur, about his father and Gen. Phil Sheridan following Arthur MacArthur's assault on the ridge. It is in William Manchester's book, American Caesar, pg 15.
"A few minutes after five o'clock Sheridan arrived on the scene. As Douglas MacArthur told the story a century afterward, the general embraced the teen-aged adjutant and said to the young man's comrades in a broken voice, "Take care of him. He has just won the Medal of Honor." If true, this would bespeak an extraordinary prescience, since the award, owing to red tape, was not made until twenty-seven years later."
"When the war ended I was Lieutenant Colonel, but held the Governor's commission as Colonel, which the War Department refused to recognize."
Manchester also writes, "For 'gallant and meritorious services in the Battle of Franklin, Tenn., and in the Atlanta campaign,' [Arthur MacArthur] was brevetted again, this time to the rank of full colonel, thus becoming, at nineteen, the youngest officer of that rank in the Union Army. Henceforth he would become known throughout Wisconsin as the 'boy colonel'."