Mary Barr Clay (1839–1924) was a leader of the American women’s suffrage movement. She also was known as Mary B. Clay and Mrs. J. Frank Herrick.
A daughter of Cassius Marcellus Clay and his wife Mary Jane Warfield, Clay married John Francis “Frank” Herrick, of Cleveland, Ohio, in 1866. The couple had three sons and then divorced.
In 1878, Clay’s parents also divorced, leaving her mother Mary Jane Clay homeless after she had managed White Hall, the family estate, for 45 years. This inequality galvanized Clay into joining the women’s rights movement, and she soon brought her three younger sisters with her. Laura Clay, the youngest, also became very active in the movement.
In 1879, Mary Clay Herrick went to St. Louis, Missouri to attend the tenth anniversary of the National Woman Suffrage Association. There she met Susan B. Anthony and arranged for the suffrage leader to speak in Richmond, Kentucky.
Herrick was elected president of the American Woman Suffrage Association in 1883. She corresponded with Anthony, Lucy Stone, Alice Stone Blackwell and other leading suffragists. She is credited with drawing her younger sister Laura Clay into the women’s rights movement. The younger Clay became so active that she became better known as a women's rights advocate.
Clay Herrick is interred at Lexington Cemetery.