Allison Mayfield, Texas secretary of state and chairman of the Railroad Commission, the son of James and Sallie (D'Guerin) Mayfield, was born on a farm near Overton, Texas, on December 2, 1860. He attended county public schools, then studied at Henderson College and Sam Houston Normal Institute. Although his grades were in the upper level of his graduating class, he failed to graduate because a fever kept him bedridden for an extended time. Rather than return to college to complete his studies he decided to prepare for a legal career. He taught for two years in Rusk and Smith County schools, then read law at the office of Horace Chilton at Tyler. Mayfield was admitted to the bar in 1883 and established his first practice at Sherman the following year. The young lawyer soon established a reputation for himself; in 1889 residents elected him city attorney. His first action in office was to codify the city ordinances. In 1891 he returned to private practice. Mayfield was married to Lula Chapman, and they had one daughter.
Beginning in 1882 he served annually as a delegate to the Democratic state convention. In December 1893 he was selected to become an assistant attorney general to Charles A. Culberson. The next year Culberson became governor and appointed Mayfield secretary of state, an office he held for only one term, 1895–97, before resigning in order to qualify for the Railroad Commission. For the next twenty-six years he served on the commission. In 1907 he became chairman. Under his leadership the commission became an efficient, effective state agency that often reflected the business progressivism that characterized Texas politics of the day. He was nicknamed "Chief" by his staff. His duties as railroad commissioner often took him to Washington, D.C. One such trip in January 1923 weakened his already fragile health. A severe cold forced him to leave the capital and return to Sherman, where he died on January 23. He was buried at the city's West Hill Cemetery.