William Glenmorgan was a big-game trapper, explorer, and naturalist located in the interior of Africa of Earth-One. Under the nickname of "Congo" Bill, he had for years operated as an adventurer, in the forefront of dangerous scenes around the world though mostly in the safari, helping to save innocents time and again. During his first adventures, Bill was mainly associated with noted botanist Professor Kent and a chimp known as O'Toole, and when World War II erupted Bill revealed his participation in World War I as an air ace which meant by 1940 he was himself at least 40 years old. His counterpart was an international freelancer known as Whistler Will, who alongside his pals Gunner Bill and Fog Fortune made up the aerial aviator adventurers known as the Three Aces. They likewise were involved in the War at the same time, only a universe away!
On Earth-One, Congo Bill eventually became employed with World-wide Insurance Company, and became the guardian of Janu the Jungle Boy who was a lad who lost his parents in the African Congo. Still later, Bill was given a ring by his old friend Kawolo which allowed him to transfer his mind into the body of Congorilla, a powerful golden simian. As Congorilla, Bill would have a few adventures on his own and later alongside the Earth-One Superman. After this, Bill retired into corporate life, founding a business in sub-Saharan Africa with his now grown disciple, Janu who had returned from extensive education in America. Meanwhile, Congorilla was kept safely in Bill's care, seeming to not age a day. Eventually this brought him to the attention of the Immortal Man who recruited both the man and his furry alter ego to join the Forgotten Heroes and combat Vandal Savage as well as the so-called Forgotten Villains. After these cases, Congo finally retired leaving his protégé Janu to operate his now thriving business... while presumably Professor Kent had long since expired. Whistler, Gunner and Fog all disappeared in the mid-1940's, presumably killed during the War.