John Lawrence Sullivan was an American professional boxer born on April 15, 1858, in Roxbury, Massachusetts. He is often regarded as the first heavyweight champion of gloved boxing, holding the title from 1882 to 1892. Sullivan was known for his powerful punches and charismatic personality, which helped popularize the sport during his era. Sullivan's boxing career began in the bare-knuckle era, but he transitioned to gloved boxing as the sport evolved. He was a key figure in the establishment of boxing rules and regulations, contributing to the development of modern boxing. Sullivan retired from boxing in 1892 and became a celebrated public figure.