In 1903, he quietly married the former Mary Ann Linton, widow of John Hamilton Morgan (1842–1894), who had been a representative to the Utah Territorial Legislature. This marriage ran contrary to the LDS Church's decision to ban polygamy in 1890. Years later Matthias F. Cowley, the official who performed the ceremony, was stripped of his priesthood by the LDS Church. When the marriage came to light, Udall was never sanctioned, but he was forced to cease marital relations with Mary. He did, however, continue to support her and her children (from her marriage to Morgan) financially until the children reached adulthood.
