What boxer's nickname was 'Gentleman Jim'?

James John "Gentleman Jim" Corbett (September 1, 1866 – February 18, 1933) was an American professional boxer and a former World Heavyweight Champion, best known as the man who defeated the great John L. Sullivan. Despite a career spanning only 20 bouts, Corbett faced the best competition his era had to offer; squaring off with a total of 9 fighters who would later be enshrined alongside him in the International Boxing Hall of Fame.

In 1854, Jim's father, Patrick Corbett, had emigrated from Ballycusheen, Ballinrobe, County Mayo, Ireland to the US. James Corbett returned to Ballinrobe in 1894, and among the highlights of his visit were the boxing demonstrations he gave in Ballinrobe Town Hall. The proceeds from the event's entrance fees were donated for the upkeep of Partry Church, where his uncle, the Reverend James Corbett, was then parish priest. He also donated a stained glass window to the church. He also coached boxing at the Olympic Club in San Francisco. He stood at 6 ft 1 in (1.85 m), with a reach of 73 inches (185 cm).