Mary Louise McKellar Herndon, the eldest of eight children, was born to John Alexander McKellar and Elizabeth (Moore) McKellar in Marion, Perry County, Alabama, on November 11, 1840. Her family moved from Alabama to Union County, Arkansas, before settling in Henderson County, Texas. Her parents were members of the planter class and owned eighteen slaves in 1850 and forty-three slaves in 1860. Their prosperity enabled them to send their children to school. Mary graduated from Baylor University, located at that time in Independence, Texas. McKellar married William Smith Herndon on her twentieth birthday on November 11, 1860. After graduating from McKenzie College during 1859, he continued his studies in law. Mary Herndon became pregnant shortly afterward and on July 29, 1861, delivered a male child who died soon after birth. She described this event as her “first great sorrow in life.”
Mary’s father provided Herndon and her husband with a home in Tyler, Texas, during September 1861. The couple housed her siblings and cousins while they attended school. Her husband enlisted in the Confederate Army in December 1861. Mary Herndon for a time lived with her parents in Henderson County, where her husband visited whenever possible while he served in the Confederate Army. He was discharged in June 1865 and had attained the rank of captain.
Mary Herndon gave birth to eight children between 1863 and 1880—William Sidney, Mary Florence, John Henry, James McKellar, Elizabeth (Bess), Grace, Charles, and Hugh. All eight of these children survived to adulthood and became suffragists, including two daughters who worked in the suffrage movement. Herndon served as a pious member of the First Baptist Church of Tyler. She, along with nineteen other members, pledged $500 each to rebuild the church in 1883 after it had been destroyed by fire. During 1908 and 1909, Herndon was the only woman to serve on the church building committee and the planning committee when the members of the church voted to construct a new building. From the late nineteenth century onward, she became more involved in the temperance movement and the woman suffrage movement.
William Herndon practiced law in Tyler before and after the Civil War, and he later entered national politics. He was elected to the United States House of Representatives in 1871 and served until 1875. Due to his work as an attorney, he and his wife were prominent members of Tyler society. William Herndon stood out as a prominent Texas lawyer who was staunchly prohibitionist. He often spoke across Texas on this issue, including a speech in Lampasas on July 26, 1887. His upcoming oratory was advertised in the Dallas Morning News.
Mary Herndon became deeply involved with prohibition. On May 15, 1891, members at the state convention of the Woman’s Christian Temperance Union (WCTU) elected her to represent Texas as one of two delegates to the national convention. Programs from the state WCTU conventions, such as the conventions of 1895 and 1903, listed Herndon as one of many vice presidents reporting to the convention. The presidents of district WCTU groups served as vice presidents at the state convention. She maintained the third district presidency for many years, and she represented the WCTU at various state and international events. During June 1903 Herndon traveled to Geneva, Switzerland, as the Texas representative at the World’s Woman’s Christian Temperance Union meeting. The WCTU appointed five delegates, including Mary Herndon, to attend a meeting of the Mothers’ Clubs of Texas during 1909.
In 1913 Mary Herndon organized the Smith County Equal Franchise League. She served as one of four vice presidents, and her daughter, Elizabeth H. Potter served as the head of the publicity committee. In addition to her temperance and suffrage work, Herndon maintained an active presence in various charitable and church works, including her support of the Buckner Orphans’ Home. Mary Louise Herndon died on July 29, 1919, while vacationing in Chautauqua, New York, where she had spent many of her summers. She was buried in Oakwood Cemetery in Tyler, Texas.