As with many of his contemporaries, Proctor's opportunity to work with some of the greatest sculptors of his day, coupled with the opportunity to create his own large, albeit temporary, pieces presented itself in the guise of the World Columbian Exposition of 1893 in Chicago. Proctor later was called upon to produce works of various Western themes, mostly figures of native animals, but also a cowboy and Indian that were to form the genesis of his later works, "The Bucking Bronco" and "On the War Trail", both found in Denver.