Of Jessop's four mounts in the Kentucky Derby, his best result was two third-place finishes. In 1946, he was third on Hampden behind eventual Triple Crown winner, Assault. Guiding the great Hall of Fame mare Gallorette, he won the Queens County Handicap against male horses in 1947.
Jessop's most notable achievements in the Kentucky Derby were two runner-up finishes. In 1946, he came third on Hampden behind Triple Crown champion Assault. With guidance from Hall of Fame mare Gallorette, Jessop won the Queens County Handicap against male competitors in 1947.