Otis Crandall Davis was an American athlete, winner of two gold medals for record-breaking performances in the 400 m and 4 × 400 m relay at the 1960 Summer Olympics. He set a new world record of 44.9 seconds in the 400 m and became the first person to break the 45-second barrier. Otis Davis (United States) set the men's 400 m world record of 44.9 in Rome, Italy on September 6, 1960. It stood 2.7 years, until Adolph Plummer's 44.9 on May 25, 1963 (equalling it). Wiki link