John L. Thunder was born on 7 July 1917, a Saturday - the seventh day of the seventh month in a year ending in a 7 and on the 7th day of the week. This coincided with the 7th Circle of the Mooon Lahseen in the the calendar of the small Asian country of Badhnesia. The high priest of that country sent agents to kidnap the child, and in a ceremony which involved a belt bearing the Eternal Zone of the Zodiac being place around the child, the enchanted words Cei-U (Say You) were spoken 7 times.
Thus a spell was cast upon the boy that would be activated on his 7th birthday. Because enemies of Badhnesia discovered the powers the child would have, they tried to capture him, but he was returned - with the aid of a birthmark - to his rightful parents in the US. Johnny was unaware of the powers he had until he was 22. He was at the first meeting of the JSA and became their mascot - until the Flash (Jay Garrick) resigned his membership and Johnny was chosen totem. During WW2 Johnny joined the U.S. Navy.
When that conflict ended, Johnny was 28 (4x7) - a power high. After that year, the high priest of Badhnesia cast a spell that gradually reduced Johnny's powers that the Thunderbolt only responded in about 1 in 4 calls. Eventually Johnny's powers disappeared completely and he had to resign from the JSA, his place being taken by Black Canary who he had a crush on.
Johnny Thunder would later join the JSA on various adventures and battles. One battle would be when he and the rest of the JSA would sacrifice themselves and enter a limbo dimension.
This was to stop Ragnarok and they would be in an eternal battle. This was caused by the actions of Adolf Hitler in April of 1945.
The absence of The JSA would not last long and they would be freed from the limbo dimension. He would leave The JSA once more and ventured to the island of Bahdnesia and discovered there were no more priests. He realized they had to leave or starve to death, there were only a handful in the 1950's when the spell was cast. He later suffered from Alzheimer's disease and repeatedly lost his pen where the Thunderbolt was stored. Jakeem Williams would later be handed the pen and would release the Thunderbolt. Jakeem took the name Jakeem Thunder or Johnny Jakeem Thunder. In a battle with Solomon Grundy, Johnny Thunder is cured of his Alzheimer's disease and his body is taken over by the Ultra-Humanite, to control the Thunderbolt. Jakeem Thunder is one of the free heroes when the Ultra-Humanite takes control of the planet. Jakeem is able to gain control of the Thunderbolt and Johnny loses his life at the end of the battle. The Thunderbolt merges with Johnny and creates Johnny Thunderbolt. The Thunderbolt eventually quits displaying his likeness but continues to talk like him. Johnny's body is laid to rest in the Valhalla cemetery for heroes. Johnny Thunder does come back as a reanimated corpse in Blackest Night.
Johnny Thunder is closing in on a century of life and has been living in retirement homes the past 37 years. He has a great grandchild and is one of the last remaining heroes to remember what has been lost to the manipulations of time. Wally West contacts him and reveals the members of the JSA still live and he must find them.