In The Spell of the Yukon (1916) she has the leading female part in a feature starring Edmund Breese, which is adapted from a poem by Robert W. Service. Service is known as the Kipling of the North. Mayo performs the role of Hattie Fenshaw in Who's Your Neighbor? (1917).
International spy, Dr. Karl Graves, was arrested in Lima, Ohio, where he traveled after watching Mayo perform at the Empire Theater in New York City. Graves authored Revelations of the Kaiser's Personal Spy. Mayo was in Lima with her manager, Phil Selznik, when Graves was apprehended, stopping first in Bucyrus, Ohio, when she left New York.
Portsmouth, Ohio was one of the thirty American cities Mayo toured in 1917. After the screening of one of her feature films, she discussed her movie career with the audience. A reception was held in the lobby of the Columbia Theater in Portsmouth. Aside from promoting movies, Mayo utilized her tour to recruit troops for service in World War I and to sell Liberty Bonds. She was assigned to the recruiting department of the U.S. Navy. She received a solid gold medal representing the American flag from the hospital corps in recognition of her service to the government. Mayo was one of the first women of the stage to be awarded the right to wear the button of the Liberty Legion.
Mayo plays the scatterbrained Mrs. Chadwick in The Hottentot (1921). One reviewer complimented her acting as a bright characterization. In The Shock (1923), starring Lon Chaney, Mayo was compared to Mary Alden in her rendition of Ann Cardington, queen of the underworld. She was in the supporting cast of Dont Marry For Money (1923) along with Edith Yorke and Charles Wellesley.
Mayo appeared with some of the most popular actors of her era. She made For Sale (1924) with Adolphe Menjou, Tully Marshall, and Vera Reynolds. The New York Times reviewed the movie unfavorably, comparing it to a discarded Daisy Ashford effort. The heroine resides in a mansion of Louvre-like dimensions. When her father loses his wealth entirely, he comes up with the idea of having his daughter, Claire Windsor, marry a reprobate, a rich one.