Thomas Lindsay Blanton was born in Houston, Texas, on October 25, 1872, a son of Thomas Lindsay and Eugenia (Webb) Blanton and brother of Annie Webb Blanton. He attended the public schools of Houston and La Grange and graduated from the law school of the University of Texas in 1897. He married May Louise Matthews, daughter of John A. and Sallie (Reynolds) Matthews, in 1899, and they had five children. Blanton began the practice of law in Cleburne but soon moved to Albany. There he practiced until 1908, when he was elected district judge. He was reelected to that office in 1912. In 1916 he was elected to the United States Congress as a Democrat; his first tenure ran from 1917 to 1929. In 1928 he did not seek reelection but ran unsuccessfully for the United States Senate. Upon the death of his successor, Robert Q. Lee, in 1930, he again won election to Congress. He remained in the House until 1937. He served on the committees on claims, education, irrigation and arid lands, railways and canals, woman suffrage, Indian affairs, and the District of Columbia. In 1932 he moved to the appropriations committee, where he remained until 1937.
Early in his career Blanton incurred the wrath of Samuel Gompers and the labor leadership. In World War I he favored a "work or fight" amendment to the draft law. He opposed the railroad strike of 1921. He received many threats, and his car was once fired upon near Washington. In 1924 he proposed to stop all immigration for five years. In 1926 he forced the resignation of a District of Columbia commissioner for overcharging veterans in guardian fees. He caused an investigation at St. Elizabeth's Hospital that resulted in the court's declaring forty-five inmates sane and releasing them. In 1928 he introduced a bill to stop immigration for seven years, to require all aliens to register, and to deport those who did not become citizens. In 1935 he introduced a bill to outlaw Communists in the United States. In his long career he consistently opposed extravagance. On May 28, 1919, he introduced a resolution calling upon all government departments to furnish a list of employees earning money outside the government and the names of all relatives on the payroll. All his fellow Texans voted against the resolution. His opposition to all congressional junkets and fringe benefits voted for themselves by Congressmen caused ill feeling toward him among his colleagues.
After being defeated in 1936, Blanton practiced law in Washington until 1938, when he returned to Albany to practice there. During World War II he urged President Franklin D. Roosevelt to ask Congress to pass promptly a law fixing the death penalty for strikers in wartime. In 1954 he withdrew at his wife's request from a race for Congress against Omar Burleson, who was seeking a fifth term.
The Dallas Morning News once observed that every delegation needed one Tom Blanton. In Congress he had a record of near perfect attendance and offered more objections to appropriations than any other member. Upon his retirement, the Washington Post said that he had saved the government millions of dollars and would be missed. He died in Albany on August 11, 1957, and was buried in the Albany Cemetery.