First Appearance: Marvel Mystery Comics #21 (July 1941).
Golden Age Appearances: Marvel Mystery Comics #21-45, #49-74, Human Torch Comics #4-5.
Modern Appearances: Avengers #97, Marvel Premiere #29-30, Invaders #6 & #35-37, Marvel Two-in-One Annual #1, What If v1 #4, Captain America #284-285, Captain America Annual #7, 13, 4 #1.
Years Active: 1941-1950.
In the Golden Age Jeffrey Mace was a newspaper columnist and reporter who was very patriotic and, inspired by Captain America (I), put on a patriotically-themed costume and began to fight crime, assisted by Mary Morgan. As time went by he got involved in a number of cases, even briefly acquiring a sidekick, Miss Patriot. Then he disappeared, as did all the other Timely heroes.
Then, in the modern era, he was brought back and his past fleshed out. His first appearance in the modern era was in Avengers #97 when Rick Jones conjured up a number of Golden Age heroes to help stop the Kree-Skrull War. Then he was brought into the various stories about WW2. His origin was kept the same, but he was described as having done quite a bit more during the War. He was a founding member of the Liberty Legion. After the war he continued fighting crime as the Patriot, but when Captain America (II) was killed in action the Patriot stepped into the uniform and became Captain America (III), sidekicked by Bucky (II) and assisted, as always, by Mary Morgan. Mace, as Captain America (III), was active with the All-Winners Squad for a few years; when Bucky (II) was injured and retired in 1949, Mace took on Golden Girl (I) as a partner.
Mace retired from crimefighting, as Captain America (III), in 1950. The Golden Girl (I) retired with him, and at some point after their retirement they married. Years later Mace was shown dying of cancer as an old man in Captain America #285; what happened to Golden Girl (I) and Mary Morgan (who undoubtedly was heartbroken that Mace chose Golden Girl (I) rather than her to be his wife) has not been gone into.
The Patriot had no superpowers but was very athletic and a good fighter.