Max was a ordinary army cadet who was given strength augmentation treatment, arranged by his (corrupt) commanding officer, in hopes of creating another “super-soldier” similar to Captain America and Nuke.
The process seemed to work well on G.I. Max who was deployed to fight against Captain America and Ms. Marvel who had uncovered the corruption in the army. During battle, Max was accidentally shot and killed by his commanding officer.
If not for his death, it was suggested he could have replaced Captain America, a role which ultimately went to John Walker.