Mayborn published the Temple Daily Telegram, the Killeen Daily Herald, the Sherman Democrat, and the Taylor Press in Temple, Killeen, Sherman, and Taylor, respectively. He established KCEN-TV, the National Broadcasting Company outlet for both Temple and nearby Waco, the seat of McLennan County. Mayborn was also a political confidant of Texas Democrats, U.S. President Lyndon B. Johnson, Governor John B. Connally, and U.S. Representatives W.R. Poage and Speaker Sam Rayburn, Secretary Oveta Culp Hobby of the former United States Department of Health, Education and Welfare, and U.S. Secretary of Commerce Jesse H. Jones. He cast a crucial vote on the Democratic State Central Committee to certify Johnson's nomination to the U.S. Senate in 1948. By the 1970s, with the defection of Connally to the Republican Party (GOP), Mayborn began to support some GOP candidates.
The Texas Daily Newspaper Association offers the annual Frank Mayborn Award for Community Leadership to recognize a publisher or other newspaper executive who contributed during the past year to the improvement of society.
He received a bachelor of arts degree in 1926 from the University of Colorado at Boulder. Mayborn worked as a correspondent for several publications while in high school (Dallas Dispatch) and in college (Denver Post and United Press International). Thereafter, he was an advertising salesman for the Dallas News (since Dallas Morning News) and then served in management positions for the Northern Texas Traction Company in Fort Worth.
In 1952, he became, first, part-owner and, then, sole owner-operator of the Killeen Herald (subsequently the Killeen Daily Herald). In 1959, he obtained the Taylor Press in Williamson County east of Austin. He sold the Taylor Press (later Taylor Daily Press) in 1974 and the Sherman Democrat in 1977 but continued as editor and publisher of the Temple and Killeen newspapers until his death.
Mayborn was also a radio and television pioneer. In 1936, he started radio station KTEM in Temple. In 1945, he founded WMAK radio (now WNQM, a Christian station) in Nashville, Tennessee. In 1953, he founded KCEN-TV, named "CEN" for "Central Texas".
At thirty-nine in 1942, Mayborn enlisted in the Army as a public relations officer. In 1944, he joined the staff of General Dwight D. Eisenhower as assistant chief of the U.S. public relations office. He received a Bronze Star and left military service as a major in 1945. He remained active in military matters, having served on the civilian advisory board for most of the commanders at Fort Hood. In 1968, he accompanied an old acquaintance, General Bruce Clarke, to South Vietnam on a fact-finding tour. On his return, he reported to President Johnson on the reliability of the controversial M16 rifle. In 1979, Mayborn was awarded the Creighton W. Abrams Medal, named for the second U.S. commander in the Vietnam War, for his contributions to the Army.
The state committee was asked to declare the winner of the primary after supporters of former Governor Coke R. Stevenson, a conservative Democrat, accused Johnson's campaign of fraudulent voting practices, particularly in Jim Wells County, one of the south Texas "machine" counties controlled by the Duval County political patron, George Parr. Eighty-seven primary votes were in dispute.
Mayborn was summoned from a business trip in Nashville, where he owned a radio station, by John Connally, then Johnson's campaign manager, to cast the deciding vote in the committee's 29-28 decision to declaring Johnson the winner. U.S. Supreme Court Justice Hugo L. Black, a former U.S. senator from Alabama, declared that the Democratic committee would have the sole power to select the nominee, a crushing blow to the Stevenson campaign. Stevenson, thereafter, embittered at the outcome of the senatorial nomination, headed the "Democrats for Nixon" Committee in Texas in 1960, when Johnson was the Democratic vice-presidential nominee on the ticket headed by then Senator John F. Kennedy of Massachusetts.
Mayborn was also involved in the development of many Bell County institutions. He served on the advisory board of the acclaimed Scott & White Memorial Hospital and played an important role in the location of Texas A&M University Medical Center in Temple. A longtime advocate of a convention center for Temple, Mayborn donated over fifteen acres of land for the Frank W. Mayborn Convention Center, which was completed in 1982. The facility includes the Mayborn Museum Complex.
As an advocate for education, Mayborn was active in the founding of the two-year Central Texas College near Killeen, which services many military personnel from Fort Hood. He also started the annual Bell County spelling bee. He endowed a chair at Texas Tech University in Lubbock. Mayborn served on journalism advisory boards at both the University of Texas and Texas A&M. He established the Mayborn Graduate Institute in Journalism at the University of North Texas in Denton north of Dallas. Mayborn also established a journalism chair at Baptist-affiliated Baylor University of Waco. He was a trustee and a donor to George Peabody College in Nashville.
Mayborn worked with Congressman Poage to obtain two Central Texas reservoirs, Belton Lake and Stillhouse Hollow Lake. He also worked to obtain the designation of the Killeen-Temple-Belton-Fort Hood area as an standard metropolitan statistical area though the four units are not directly contiguous. He was president of the Texas Publishers Association in 1941 and of the Southern Newspaper Publishers Association in 1961.
Over the years, Mayborn received numerous awards, including an honorary doctorate from the University of Mary Hardin-Baylor in Belton and the Distinguished Citizen Award of the Boy Scouts of America, an organization that he tirelessly supported over the years. He was inducted into the Communications Hall of Fame at Texas Tech. He also supported numerous charitable projects through the Frank W. Mayborn Foundation.
Mayborn was married to (1) the former Ruth Whitesides (1906-1977) from 1929-1946 and (2) the former Wythel Killen (1912-2001) from 1947-1972. Both marriages ended in divorce. In 1981, Mayborn married the former Anyse Sue White (born ca. 1936), who, thirty-three years his junior, succeeded him as editor and publisher of the Temple and Killeen papers.
Mayborn was a Mason and a Presbyterian. He died of heart attack in Temple.