Nellie Tayloe Ross was elected on November 4, 1924 and sworn in as governor of Wyoming on January 5, 1925. She won the special election held to replace her husband, William Ross, who died on October 2, 1924 while serving as governor of Wyoming. Wyoming had the first female governor by 15 days. Miriam A. "Ma" Ferguson was sworn in as governor of Texas on January 20, 1925. Ms. Ross lost her reelection bid two years later.

More Info: en.wikipedia.org