Appearance: Uncanny X-Men #215 (March 1987).
Appearances: Uncanny X-Men #215-216, 223, 225-227, 255, New Mutants #65, X-Factor #30-31, Captain America #346.
Years Active: 1941-present.
Louis Hamilton, aka Stonewall, was a mutant whose power made him akin to a stone wall, hence the name. He teamed up with the Crimson Commando, Stonewall, Super Sabre, and Yankee Clipper (I). The quartet were active during World War Two, although it is not known if they teamed up any of the other heroes of the time or with groups like the Liberty Legion or the Invaders.
After the war Stonewall, along with the Crimson Commando and Super Sabre, returned to Massachusetts and began fighting crime, the Yankee Clipper (I) apparently having died during the war. In the early 1950s the trio offered their services to the American government in the fight against Communism, but the government declined their offer (for unspecified reasons) and instead persuaded the group to retire from active crimefighting.
Some time after that--perhaps a few years, perhaps a few decades, it was never made clear--the trio, disgusted with modern society, began capturing and playing "The Most Dangerous Game" with criminals and those they disapproved of. They came in conflict with and were defeated by Storm and the X-Men. Eventually the trio joined joined the government-sponsored group Freedom Force. Stonewall was eventually killed by the villainous group the Reavers.
Stonewall could not be knocked down and had at least low level invulnerability and super-strength.