Roy Lincoln was a brilliant chemist who was assisting his father, a famous explosives expert, in working on a new, incredibly powerful explosive chemical known as 27-QRX. Nazi agents, intent on stealing the formula, confronted the two chemists in the laboratory, and one shot and killed Roy's father. Roy fought the agents, and to prevent them from getting their formula, swallowed the chemical. The result was that the tremendous explosive power in the chemical was somehow concentrated in Roy's hands, into energy he could release with destructive force. Using this power, Roy defeated the agents.

Lincoln adopted the costumed identity of the Human Bomb in order to usehis new powers to battle crime and subversion. He had to wear "fibro-wax" gloves at all times so as not to release his power accidentally.

The Human Bomb joined the wartime All Star Squadron and was one of the Freedom Fighters who followed Uncle Sam to Earth-X and fought the axis powers on that parallel world, which had no super heroes of its own.

On Earth X, World War Two carried on for decades and the Nazi's eventually took over the planet. However, with the help of the JLA and JSA, the Freedom Fighters, including the Human Bomb, eventually overthrew the Nazi regime.