Growing up in a formidable Chicago neighborhood, he began boxing as a kid, pounding the bag with his brother after school at a local gym.
[5] Beginning prize fighting in 1896 at the age of 16, he abandoned his aspirations to become a professional artist, and dropped out of high school to find time to train.
[3] In his early career, he took tips from Charles Kid McCoy, a former welterweight boxing star, and 1897 World Middleweight Champion, who helped him master his trademark "corkscrew punch", a twisting blow delivered as a hooking uppercut.
On November 22, 1898, he defeated Charles Roden in a ninth-round technical knockout at the Lenox Athletic Club in New York City.
On May 19, 1899, Harris knocked out the 1890 World Featherweight Champion, "Torpedo" Billy Murphy in the fourth round at the Star Theater in Chicago, Illinois.
[3] Harris met Chicago Jewish boxer Sig Hart twice in Iowa, on July 7, and August 4, 1899, winning in a fifteen-round points decision and a six-round knockout.
Harris used his reach to his advantage throughout the bout, landing solid blows and effectively blocking those of Hart to take the points decision.
Hart was an accomplished boxer in his own right, another hero of the Chicago Jewish Ghetto crowd, and faced many of the same opponents as Harris including the champion Torpedo Billy Murphy.
[8] On September 1, 1899, Harris, at 112 pounds, fought a draw with the great bantamweight Jimmy Barry at the Star Theater in Chicago, Illinois.
[12][13] Flanagan was considered by many sources to have taken or competed for the 105 pound bantamweight championship of the World in February 1898 against Danny Dougherty or September 1898 against Casper Leon.
[3] According to Cyber Boxing Zone, on October 18, 1899, Harris defeated the accomplished bantam and featherweight Tim Callahan in a six-round points decision in Chicago, though other sources lack this record.
[3] On October 26, 1900, Boxing at 118 pounds, Harris defeated Jimmy Reagan, at the Star Theater in Chicago in a six-round points decision.
Reagan was an accomplished bantamweight who would later contend for the World Featherweight Championship against the long reigning champion Abe Attell in September 1903 and June 1904.
[15] On November 27, 1900, Harris lost one of his last six round Chicago-based fights against fellow Chicago boxer Clarence Forbes, at Tattersal's.
On April 30, 1901, McFadden would contend with Danny Dougherty for one version of the World Bantamweight Title, winning in a ten-round disqualification in his hometown of San Francisco.
On March 8, 1901, Harris took the World Bantamweight Championship against British boxer Pedlar Palmer at the National Sporting Club in London in a fifteen-round points decision.
Rice would contend for the World Featherweight Championship and later become a close associate and frequent opponent of fellow New London boxer and future Panamanian Heavyweight Champion Abe Hollandersky.
On March 26, 1902, Harris met Danny Daugherty at the Penn Art Club in Philadelphia, losing in a six-round newspaper decision.
[4] By newspaper decision, in their last meeting on December 14, 1905, Harris bested fellow Jewish Chicagoan boxer Barney "Kid" Abel in three rounds at Jack Cooper's Athletic Club in New York City.
By 1918, Harris was working as a broker and in 1919 purchased a seat on the New York Stock Exchange, as a member of Robinson, Duff, and Company.
During his days working in theater, Harris had struck up an acquaintance with J. Robinson Duff, formerly a heavyweight boxer who had turned to Wall Street to make a living.