In 1917 Roth made her Broadway debut as the character "Flossie" in "The Inner Man". Her film debut occurred the following year, when she performed as an extra in the government documentary "Pershing's Crusaders". She and her sister Ann also toured together during this period as "Lillian Roth and Co.", although at times they were billed as "The Roth Kids". According to Lillian's autobiography, one of the highlights of their tour was meeting U.S. President Woodrow Wilson, who attended the girls' vaudeville act and afterwards allowed them to ride with him briefly in his chauffeur-driven car.