As a graduate student, Cathy Webster participated in an unsanctioned psychology experiment involving subliminal recordings. She was subliminally programmed to hate all men, and her body subjected to "mutagenic radiation". The radition enhanced her body to peak human conditioning similar to the Super Soldier Serum that enhanced Captain America. Cathy eventually overcame her brainwashing and discovered the woman in charge of the experiment was the criminal scientist named Superia. She also crossed paths with the criminal Baron Zemo and fought the Serpent Society member Coachwhip.
Captain America took Cathy and another novice hero, Jack Flag, under his wing and trained them both. The duo also inherited Captain America's network of computer operatives, the Captain America Hotline when he temporarily lost his powers due to the breakdown of the Super Soldier Serum in his bloodstream.
Like Captain America, Cathy has been augmented to peak human conditioning. She has reached a high level of martial arts prowess, including basic acrobatics and street fighting techniques, from training sessions with Captain America and Jack Flag.
Free Spirit has the peak human strength possible for a woman of her age, height, and build.