Claim: Federico Plummer (born on April 10, 1929) made his professional debut, a sixth-round knockout of Sam Langford on May 23, 1947; then he won his first six fights before losing to Mike Ross in April 1948.
Evidence: Federico Plummer (born April 10, 1929) is a former lightweight professional boxer from Panama. Federico Plummer made his professional debut, a sixth-round knockout of Sam Langford on May 23, 1947. Plummer won his first six fights before losing to Mike Ross in April 1948.