James Jackson Jeffries (Jim) was a great fighter at the turn of the century, when boxing styles and techniques were a bit cruder than today but fighters were more rugged and possessed greater spunk and stamina.
He was a big, strong heavyweight who struck sledge-hammer blows with each fist, similar to Rocky Marciano and George Foreman of more recent years. Jeffries often fought from a crouch and sprang forward with dangerous punches.
Fighting in a time when hard work and manual labor was at its peak, Jeffries was always in magnificent physical condition. He was rugged beyond belief, possessed a granite chin, and absorbed punishment without blinking. In addition, he was a patient fighter who seemed to possess unlimited endurance.