[4] According to BoxRec, Ferns began his career by 1896 with six straight knockouts of boxers Jack Dougherty, Tom Mackey, Harry Pigeon, Cass Whitman, Ed Doyle, and Fred Ross.

In 1897, Ferns fought in some larger cities and New England venues, meeting Kid Gardner in a draw in Chicago in February, and Izzy Straus and Lou Demonge in Brooklyn Clubs in June.

On January 15, 1900, Ferns fought his first bout billed as a World Welterweight Title, defeating "Mysterious" Billy Smith at the Hawthorne Athletic Club in Buffalo, New York.

[5][6] On August 13, 1900, Ferns defended his World Welterweight Championship against contender Eddie Connolly, before a crowd of 1800 at the Olympic Club in Buffalo in a fifteenth-round technical knockout of a planned twenty-five.

In February, he defeated Mike Donovan again at the Hawthorne Athletic Club in Baltimore in a 20-round points decision listed as the 145 pound championship of the world.

Continuing to establish his legacy as the Welterweight Championship, Ferns defeated Matty Matthews on August 30, 1900, at the Lightguard Armory in Detroit, Michigan in a fifteen-round points decision.

The Detroit Free Press wrote, "Rube Ferns demonstrated that he is a hard hitting, game and dangerous man and clearly entitled to the honor which he now holds, that of welterweight champion.

Ferns re-took the title on May 24, 1901, in Toronto, Ontario, Canada in a tenth-round knockout which may have been a close bout prior to the final blow.

[6][11] Ferns had two more important defenses of the Welterweight title, first on September 23, 1901, against the lightweight champion Frank Erne in front of an enthusiastic crowd of 4,500 at the International Athletic Club in Ft. Erie, Ontario, Canada in a ninth-round knockout.

In another bout which was very likely a title defense, Ferns defeated Charles Dutch Thurston on November 28, 1901, at the Light Guard Armory in Detroit, Michigan in a full fifteen round points decision.

On December 18, 1901, Ferns lost the Welterweight Championship of the World to the great Barbados Joe Walcott, one of the greatest lightweights in boxing history.