Early career

Making a stir in his professional debut in March, 1935, at the age of 21, he knocked out Jim Dowling at the Jamaica Arena in Queens, New York. According to most sources, in an impressive display, he won his next thirteen fights, and nearly all by knockout.^[2] His two most notable early career losses against well known adversaries came against Lou Nova in 1936 in a six-round points decision and the six-foot-six Buddy Baer, brother of Max, who knocked him out in three rounds in 1937.^[1][2]

In a rare loss on January 22, 1940, he dropped a decision to Willie Reddish in a well-attended match in Philadelphia. Simon was down twice in the match, and Reddish was given eight of the ten rounds. Reddish peppered Simon's body and jaw with left hooks and right swings, and won an easy decision.^[6] In the prior month on December 6, 1939, Simon had defeated Reddish in a fourth-round TKO in Philadelphia. As was not uncommon in Simon's matches, he had a sizable weight advantage over his opponent, in this instance a remarkable fifty-six pounds. The match took a turn for the worse in the fourth when the two boxers' heads clashed, and Reddish received a bad gash on his forehead, leading to the referee ending the fight from a technical knockout in the fourth.^[7]

Knockout of Jersey Joe Walcott

In one of his most memorable victories, in a ramp up to the heavyweight title, he knocked out the legendary Jersey Joe Walcott, a future heavyweight champion, in six rounds in Newark, New Jersey, on February 12, 1940. A heavyweight in every sense, he benefitted from a remarkable sixty-two pound weight advantage in the match. Behind in points in the first five rounds, Simon unleashed a tremendous right to the mouth of Walcott 2:32 into the sixth causing the knockout, and Walcott barely moved as he was counted out by the referee.^[8][9][2]

In a well-attended match against a known opponent, Simon defeated Eddie Blunt in a ten-round points decision at the Meadowbrook Bowl in Newark, New Jersey on May 20, 1940. The last three rounds were fought in a heavy rain in the outdoor arena. Simon outweighed Blunt by 28 pounds, and persevered to pull off the win with a points victory.

In one of his best known victories against a highly rated adversary, he defeated Roscoe Toles on December 6, 1940, in a ten-round unanimous decision before 5000 at Detroit's Olympia Stadium. After the fight, boxing promoter Mike Jacobs announced his intention to match Simon with Louis for the heavyweight championship. Simon performed better fighting in close, and was unaffected by a few punches to the jaw. There were no knockdowns in the match. Though Simon was the clear winner, the Detroit Free Press wrote that Toles more than held up his end of the fight looking far better in the fourth, and that only in the final rounds did Simon, showing greater endurance, take the fight to Toles.^[10][11] He also had a heavily publicized win over Finland's Gunnar Barlund on October 7, 1940, in a ten-round points decision at New York's St. Nicholas Arena. Barlund was soundly defeated suffering a cut eye and chin early in the match, and winning no more than two of the ten rounds.^[12][13][2]

World heavyweight contender

In his first attempt at the world heavyweight championship, on March 21, 1941, he lost to reigning heavyweight champion Joe Louis before a record crowd of 19,000 at Detroit's Olympia Stadium in a 13th-round technical knockout.^[2] He was assisted in training for that match by the first African-American World Heavyweight Champion, Jack Johnson.^[14] In the most valiant effort of his career against his greatest adversary, many ringside experts gave Simon the second, fourth, sixth, tenth, and eleventh rounds. According to one source, when Louis knocked him down in the first round, it was the first knockdown of his professional career. Simon even managed to stagger Louis briefly in the seventh.^[1] Though he was down repeatedly in the thirteenth before the referee called the fight, his ability to withstand the blows of Louis and win four rounds placed him as a serious heavyweight contender in his mid-career.^[15] After the fight, Louis told reporters, "for a big guy, he was pretty good and just about as tough as they come".^[1]

He lost to Louis again in his second and final attempt at the heavyweight title, at the coveted venue of Madison Square Garden on March 27, 1942, in a sixth-round technical knockout. He was down at the bell in both the second and fifth rounds.^[2] Before 18,000 fans, Simon fought through a bruising attack by Louis, lumbering into the fourth round and connecting with a few blows, before succumbing to a brutal attack in the opening of the sixth. Louis was fighting for the Army for the first time, and though he was fitter than in his first match with Simon, he was hoping for a quick knockout to avoid injury as he received no purse for the fight. The match was a benefit for the Army Relief Fund, which helped both boxer's reputations and garnered a larger audience, including many servicemen.^[16]