Mystery always surrounded Sonny Liston. Conspiracy theorists say his death in 1970, ruled as a drug overdose, was foul play. Boxing historians look at his underachieving career and criminal past and wonder if he had mob ties. While those cases may never be closed, a recently released clue sheds more light on one of Liston’s many mysteries: his birth.

According to a late-issued birth certificate, Liston would have been just a shade under 32 the first time he fought Muhammad Ali in 1964. However his age was even questioned even then. Bert Sugar wrote that “Friends placed his [Liston’s] age closer to 40” and attributes that to the lack of stamina that lead to his first loss against Ali. If that were true, then Liston would have been born around 1925. Oh, and one more thing. At that time, he would have surpassed Jersey Joe Walcott as the oldest heavyweight champion in history. Liston would have held that distinction until 1994, when a 45-year-old George Foreman knocked out WBA and IBF heavyweight champ Michael Moorer.

Unlike other nuances, the mystery over Liston’s age does not come down to alleged mafia ties or cover-ups, just Great Depression-era circumstances. He was born “Charles L. Liston” sometime between 1930 and 1940 to Tobin, a dirt-poor sharecropper, and his wife Helen Liston in the town of Forrest City, Arkansas. Unfortunately there is no record of his birth because Liston was not born in a hospital and the State of Arkansas did not require mandatory birth certificates until 1965.

He did file for a birth certificate for legal reasons in 1953, citing his date of birth as May 8, 1932, but the chances of that being correct are very slim. His own mother said he was born on January 8, 1932. Sometimes she said it was January 18. Other times she said he was born between 1929 and 1930. Even Liston had a tough time keeping track of his own age. In 1950 he gave his age as 22, which would have his birth taking place sometime in 1928. In 1960, he testified before the Senate, saying he was born in 1933.

Over the years, debate over Liston’s age has waned. The mystery surrounding his birth is usually an addendum to an argument on the tragedy of Sonny Liston. But before you lament his plight, one place has the answer. The 1930 census hit every household in America and, sadly, kept better records than the State of Arkansas. The 1930 census also just became available, since census records are released 72 years after they are collected.

So just how old was Sonny Liston? Was he born before 1930? If you go to the National Archives in Washington, DC and pull up the microfilm for Forrest City, Arkansas you will find Tobin Liston’s 1930 census family card. But Charles L. Liston is not on it. His mother, Helen, is listed, as are his sisters Clytee, Annie and Alcora, and his brothers J.T., Leo and Curtis, who is the youngest at six months. This means that Liston could not have been born before late 1930 and that the oldest he could have been when he fought Ali the first time was 33-years-old.

While there will never be indelible proof of Sonny Liston’s date of birth, one thing is now certain: That was not an old man that Muhammad Ali beat in Miami on February 24, 1964. Sonny Liston may have even been younger than 31 at that time. The 1940 census will be released in 2012. Hopefully this will provide the final piece to one of the many puzzles of Sonny Liston.