More than a year before Pearl Harbor, at the behest of would-be dictator Andel Cobra, a fascist group called The Purple Shirts was already working to undermine America's defenses. They were opposed by a patriot named Ezra Smith, who got himself killed for his efforts. Ezra's young son, Buddy, ran off, despondent and desperately wishing there were someone to defend America from these saboteurs. Uncle Sam appeared to him in the form of Buddy's father Ezra, the Spirit of America having found the man worthy to continue it's mission.
Together Sam/Ezra and Buddy defeated The Purple Shirts. After that, working from a vision that came to Sam of the impending threats to Liberty and Freedom he and Buddy set out to gather like-minded individuals to support the cause. The first was newspaperman Clark Kent – Superman – who's contacts in the military lead him to Steve Trevor who in turn introduced the heroes to Queen Hippolyta herself; Wonder Woman, and Ray Terrill a scientist with the military who'd recently begun adventuring as The Ray.
Superman then introduced the mysterious Jericho to the group. Sam had his doubts about a hero who completely concealed his identity, but after the revelation of Augustus Freeman being a black extraterrestrial and a prominent lawyer in his civilian life the old man relented. Max Mercury – Quicksilver – one day showed up having had a vision himself. He brought Carol Martin – Wildfire – with him. While the cryptic nature of Max's involvement raised eyebrows he and Carol proved themselves able comrades.
The Freedom Fighters were the most respected and admired heroes of the Golden Age. With contacts in the media and the military they were on the front lines when WWII rolled around.
When McCarthy called the Freedom Fighters up before the House Unamerican Activities Commission as a straw man to represent the entire Mystery Man/Super Hero community it was Superman who spoke for them refusing to reveal their identities, for as much as they respected the government they simply couldn't trust the safety of their loved ones to the same people who were outing “Reds” for political gain.