Lillian Gunter, pioneer county librarian and architect of the County Free Library Law of Texas, was born at Sivells Bend, Texas, on September 15, 1870, to Addison Yancey and Elizabeth (Ligon) Gunter. Her parents had moved to Texas in the 1850s, he from North Carolina (via Troupe County, Georgia) and she from Clay County, Missouri. In 1866 her father, who served a term in the Texas legislature in 1885, bought a plantation at Sivells Bend on the Red River, where Lillian grew to womanhood. Her home became a frequent stopping place for friends and travelers eager to discuss major issues of the day with the Gunter brothers, agricultural, civic, and Democratic political leaders of North Texas. Lillian attended the local school until she was twelve. Then she entered Sacred Heart Convent in St. Louis, Missouri, where she studied for three years (1882–85); later she spent two years at the Wesleyan Institute, Staunton, Virginia. After her father's death in 1892, she managed his estate until 1901, when she and her mother moved to nearby Gainesville.
As a member of the XLI Club, a local women's literary society that also played an active role in civic affairs, Lillian Gunter took the initiative in transforming a small subscription library into the Gainesville Public Library, which she directed for ten years. This library, located in a Carnegie building completed in 1914, became the central library for the Cooke County system, which was established in 1920. On learning there was no legal way that rural people could organize and support a public library in Texas, Lillian Gunter began the crusade to pass a county-library law. She studied the systems of New York and California, traveling to both states at her own expense; enlisted the aid of legislators, the Texas Library Association, the Texas Federation of Women's Clubs, newspapers, and townspeople; wrote legislation; and fought legal battles to establish service for Texans. Her determination overcame defeat and frustration from delays, led to an awareness that the first county-library law was weak and unworkable, and brought about a new law, passed in 1917. The courts overturned this law, however. With the help of Cooke County representative George W. Dayton, who urged passage in the legislature, Gunter's continued efforts resulted in the passage of a new County Free Library Law in 1919, a statute that remains in effect.
The Cooke County Library, which Gunter founded in 1920 and directed until her death, was the second such system established under the new law (Dallam County having founded the first only a few months earlier), but the first established by petition. The direction and expansion of the library during its early years earned for its director the reputation of being an authority on library establishment and administration. Many librarians and laymen throughout Texas and the Southwest sought her advice on their problems, and in response to their appeals she made speeches and wrote numerous articles. Lillian Gunter, however, did not confine her activities to librarianship. Because of her interest in local and regional history, she became in 1925 a charter member of the Red River Valley Historical Association. She was an active member of the Texas Library Association and served as its first vice president in 1915–16, president in 1918–19, and treasurer in 1914–15. She was a cofounder in 1922 and first treasurer of the Southwestern Library Association. She died on October 10, 1926, at her mother's home in Gainesville and was buried in the family cemetery at Sivells Bend.