Thomas William Johnson was born around 1831 in Missouri, probably to John Johnson. His father was a farmer who owned $1,500 of real estate by 1850. He lived in Jefferson, Missouri, until the 1850s, when he moved to Gainesville, Texas. He married Mary Elizabeth Bradley on December 21, 1854, and they had at least three children: Edward, born around 1856; John, born around 1859; and William, born around 1862. He worked as a farmer, and by 1860, he owned $2,500 of real estate and $500 of personal property.
He enlisted in the Confederate army in August 1862, and he mustered in as a private in the 31st Texas Cavalry. The regiment took part in the Red River campaign. In May 1863, he argued that "there is an over ruling providence in this war and he will manage it as seems best to him and I think the prolongation of the institution of slavery rests upon the issue of this war if slavery is to be perpetuated we will gain the day if not I think it doubtful." In June 1864, he confessed that he was "getting very anxious for this little affair to come to a close." He believed there was "but one way for it to end & that is for the feds to give it up...[it] depends a good deal on their nex presidential election if Lincoln is elected the war will continue if not I think it will end soon after that time." He earned a promotion to sergeant in 1863, and he died of disease sometime after November 16, 1864.