Seltzer began jotting ideas onto the tablecloth, incorporating these popular entertainment forms with a roller skating theme. The name Roller Derby was trademarked on July 14, 1935 (No. 336652), and on August 13, 1935, twenty thousand spectators filled the Chicago Coliseum to see 'Colonel' Leo Seltzer's Transcontinental Roller Derby, a mythical marathon race from one end of the country to the other which incorporated both male and female participants on a banked track.
