The Patriot was introduced in the pages of Human Torch #4 (cover-dated Spring 1941 and with an on-sale date of March 31st, 1941 according to the GCD, and actually the 3rd issue in that series) in both a two-page text story
and later that same issue in a ten-page feature story.
He had a few variations in his outfit during the Golden Age, and in the 1970s when Roy Thomas brought him back as a member of the Liberty Legion during WWII, he was revealed to be the replacement for the replacement of Steve Rogers when he and Bucky disappeared after a battle with Baron Zemo.
From the Official Handbook of the Marvel Universe: Golden Age (2004),