(November 10, 1860 - July 13, 1940) Mary Florence (Tinsman) Cowell and her husband S. B. Cowell came to Texas from Missouri in 1900. Mrs. Cowell was a member of the P.E.O. Sisterhood, a philanthropic educational organization founded in 1869 at Wesleyan College in Iowa and dedicated to educational opportunities for women. Her friend Dora Hallock, P.E.O. supreme chapter organizer, visited Whitesboro in 1902. Together they organized Chapter A, the first P. E. O. chapter in Texas, in the Cowell home on this site. Mary Florence Cowell was elected president of Chapter A and was instrumental in the organization of the Texas State Chapter of the P.E.O. in Whitesboro in 1928. Elected the first Texas state president of the organization, she eventually became known as "the mother of P. E. O. in Texas.