Captain Flag is a fictional superhero created by MLJ Comics' writer Joe Blair and artist Lin Streeter. He first appeared in September 1941, in issue #16 of Blue Ribbon Comics. He shared the cover with Mr. Justice until #19 when Captain Flag was the only one to appear on the cover. He was on until the end of Blue Ribbon Comics in March 1942 with Issue #22.
His secret identity is Tom Townsend, the wealthy playboy son of an inventor father. The villain the Black Hand kidnaps him and his father, intending to torture Tom's father in order to obtain the secret of his latest invention, but Tom's father dies resisting the questioning. Before Tom, too, is killed, a great eagle crashes through the window and carries Tom off.
Training with the eagle's aerie at the top of the mountain, the healthy environment and hard living made him an elite physical specimen. When the eagle brings a US flag, he took it on as his namesake, and makes a costume out of the flag. He names his animal savior-turned-sidekick Yank the Eagle, and went on to successfully thwart the Black Hand.