What about Mr.Scarlet & Pinky?
Kirby's Fighting American (later used by Rob Liefield) as I understand it, was Kirby's way of saying "I can't do Captain America? fine, I'll make my own!"...likewise USagent/Superpatriot are likewise probably too close to Captain America to get thier own entries
Ialso agree ErikLarsen's Superpatriot (and his kids Liberty & Justice) should be included
And as a fan of Aaron Williams "PS238" I have to include American Eagle and US Patriot Act
As for the Spirit of 76...fun fact; at the time in March 1977 both Marvel and DC were putting out a WWII comic, "Invaders" and "Freedom Fighters" during one month each comic had an "evil" version of each sides heroes called "The Crusaders" (a la the "Squadron Supreme/Assemblers")
The Invader version which fought the Freedom Fighters was Americommando (Captain America), Rusty (Bucky), Fireball (human Torch), Sparky (Toro), And Barracudda (Sub-Mariner)
the Freedom Fighter version who fought the Invaders was Spirit of'76 (Uncle Sam), Dyna-Mite (Doll Man) Ghost Girl (Phantom Lady) Tommy Lightning (The Ray), Thunderfist (Human Bomb), and Captain Wings (Black Condor)....both Crusaders were supposed to be "one-off" characters with the versions losing their powers after the story ended and never seen again, the only exceptions were Dyna Mite (who became the Destroyer) and Spirit of 76 who was rescued from obscurity to become the "new" Captain America in an issue of "What IF"
side note...while the idea was agreed upon by both Marvel & DC editors, neither knew until the comics saw print that coincidentally, both companies chose to call their teams "The Crusaders"