Thomas Brooks Fairleigh was born around 1837 in Kentucky to William and Elizabeth Fairleigh. His father was a clerk of the court who owned $8,500 of real estate in 1850. Fairleigh grew up and attended school in Meade County, Kentucky. By 1860, he was working as a lawyer in Brandenburg, Kentucky, and he owned $1,000 of personal property.
He remained loyal to the Union during the Civil War. In June 1861, he attended a Unionist meeting in Brandenburg, where he delivered a “powerful and patriotic speech” in support of the Union. He received a commission as a captain in Company G of the 26th Kentucky Infantry on March 5, 1862. He was promoted to major on May 5, 1862, and then to lieutenant colonel on June 12, 1862. The regiment took part in the Battle of Shiloh, the siege of Corinth, the Battle of Perryville, the Battle of Nashville, and the Carolinas campaign. He was promoted to colonel on January 3, 1865, and he mustered out in Salisbury, North Carolina, on July 10, 1865.
Fairleigh settled in Louisville, Kentucky, after the war. He joined the Republican Party and attended the state convention in 1868. There, the delegates denounced Confederate “traitors” and called for “equal and exact justice to all men.” He married Alice R. Graham there on February 9, 1869, and their daughter Ellen was born around 1870. He worked as a lawyer in Louisville, and by 1870, he owned $9,000 of real estate and $7,000 of personal property. He employed at least one Black domestic servant. He died in Louisville on November 2, 1890.