His mother was reported to be a stout six feet and 200 pounds. White Eagle stood six feet, five inches tall, and tipped the scales at 315 pounds. Luther's sister toured the vaudeville circuit as "Hazel Kirkman, world's champion woman bag puncher."

From this impressive gene pool Luther McCarty grew to six feet five inches, 215 pounds of fighting talent. The talent, however, was not immediately apparent. His first boxing match in Sidney occurred on a hot August night in 1911. Harry Hollinger, an employee at R. Given and Sons Tannery, landed a left punch early in the fight, knocking out McCarty. The News later reported Luther's retort after regaining consciousness: "You made a dub of me, Harry, but I'm going to stick to this game and show up some of you fellows before I am through." Shortly afterward, McCarty left town. He also left behind his wife, Rhoda, and infant daughter Cornelia.

For a short period of time, McCarty apparently fought under the name of Walker Monahan. His obvious physical talents caught the eye of Billy McCarney, Philadelphia sportswriter and boxing promoter. Under McCarney's watchful eye, Luther fought his first professional fight in Culbertson, Montana, beating a fighter named Adams in two rounds.

McCarney lined up two bouts in New York City. His man beat Jim Stewart and then bested Jess Willard in a ten round bout during the summer of 1912. The New York media was less than kind in assessing McCarty's talents, however. McCarty was determined to become a champion and prove his critics wrong. In short order he fought Carl Morris, Jim Barry, Al Kaufman, and Jim Flynn. His progress was rapid. He was now ready for a shot at the title.

McCarney apparently knew that McCarty, still relatively unknown, was ready to take on Al Palzer for the championship. The Cincinnati Enquirer reported a week after the fight that McCarney had encouraged all his friends "to get a bet down on his protege, as he is a cinch to beat Palzer." Luther, then only 20 years old, was probably less certain.