Served at age 13 as a militia messenger during the Revolutionary War; was captured, becoming the only President to have been held as a prisoner of war (Washington had surrendered in the French and Indian War but was immediately paroled); served in the War of 1812, attaining the rank of major general and became a national hero after his success at the Battle of New Orleans.
Left militia to enter Virginia legislature. (Some sources claim Madison briefly assumed command of an artillery battery during the British assault on Washington during the War of 1812. If true, he would join Washington (Whiskey Rebellion) as having seen military service as commander-in-chief.)
Did not experience combat but served during Black Hawk War burying the dead shortly after battles ended.
Initially elected to the officer rank of Captain, but was mustered in and out of service during the Black Hawk War, going from Captain to the enlisted rank of Private and finishing his service in an independent spy company commanded by Captain Jacob Early. Honorably discharged without seeing combat. Also served in Stillman's Run and Battle of Kellogg's Grove
None. Adams served as chairman of the Continental Congress's Board of War (1776–1777), making him the simultaneous equivalent of today's Secretary of Defense and Chairman of Senate Armed Services Committee.
He did, however, take an active part in a naval battle against the British merchantman, Martha, on March 10, 1778; while in transit to France aboard the 24-gun frigate Boston. The ship's Captain, Samuel Tucker, later related the story that during the thick of the battle, he had discovered Adams "among my marines accoutered as one of them and in the act of defense."
None. He attempted to join the Navy during the Spanish American War but was unable as he contracted measles. Served as Assistant Secretary of the Navy from 1913 and through World War I; when the U.S. entered the war in 1917 he offered his resignation so that he could apply for a commission in the Navy, but was refused by the President. Witnessed fighting in World War I. In a post World War I publication "Harvard in the War" he is listed among the Harvard's contributors to World War I effort. He served as President during World War II.
^Ryder, Robert Randall "My War Chuck Downey Youngest Naval Aviator in WWII." Sea Classics, August 2013. "Off he went for training in Memphis, Tenn., before heading to Pensacola, Fla., for flight school, where he was commissioned as an Ensign in the U.S. Navy on July 16, 1943. Downey was the tender age of 18 years, 11 months, and 14 days when he earned his wings."