2. He supported the building of the Transcontinental Railroad by freighting supplies
By 1868 Earp was known as an experienced freighter and he began freighting supplies to the railhead of the Union Pacific Railroad as it crept westward. While at the railhead he learned to both gamble at cards and to referee boxing matches, developing a reputation as a fair but tough official. In Cheyenne, Wyoming on the Fourth of July of 1869 he officiated a fight which featured “Professor” Mike Johnson, who later taught future American president Theodore Roosevelt how to defend himself at the New York Athletic Club. The fight took place before an estimated 3,000 spectators, a significant number of fans for a bare-knuckled boxing event.