After attending preparatory school at Baylor University, he enrolled at the Bastrop Military Academy.. Sam Jr. inherited his mother’s artistic ability and was frequently drawing and sketching.
Although his father opposed secession, Sam Houston Jr., enlisted as a private in The Bayland Guards, Company C, of the 2nd Texas Infantry, commanded by his father’s friend Ashbel Smith. Before they left Texas his father visited the unit to deliver a bible from his mother to Sam Jr. inscribed, “Sam Houston, Jr., from his Mother, March 6, 1862.”
The regiment was still dressed in blue uniforms when they reached Corinth to join Gen. Albert Sydney Johnston’s army, but on the eve of battle, they received new uniforms of undyed white Jean Cloth. Some of the men said they were going to battle in their funeral shrouds. The 2nd Texas would join Gen. John K. Jackson’s Brigade and would see heavy action on the Confederate right all day.
On falling back with the regiment to Union encampments to rest for the night, Private Houston discovered that the new bible he had been carrying had been hit by a musket ball which had stopped at the 70th Psalm and possibly saved him from a fatal wound. In the fighting on April 7, Houston was not so lucky and was hit by a ball in the right groin and left for dead on the field.
A Union surgeon who examined the wound assumed the femoral artery was hit and left him to die. A chaplain, who had known his father in the Senate, located the bible and found the note from Private Houston’s mother.
He called the surgeon back who on closer examination determined that the artery was not severed. The surgeon continued treating Houston who eventually recovered and was sent to the Confederate Prisoner of War Camp Douglas, near Chicago.
Private Houston’s comrades reported him as left dead on the battlefield and for a while, his family was unsure of his fate. Eventually, he was exchanged and returned to Texas where he became a Lieutenant in a Texas Artillery Battery.
After the war, Sam Jr., enrolled in the medical department of the University of Pennsylvania in 1867, and gained a medical degree, and practiced medicine in Texas. In 1875, Sam Houston Jr. married Lucy Anderson and ceased the practice of medicine to devote time to writing poetry and short stories. Despite his father’s often expressed disapproval of novels and light reading, Jr. wrote a volume of adventure stories, published in 1892.
When his wife died in 1886, Sam Jr., returned to Independence to live with his sister Margaret Lea Houston Williams, until his death on May 20, 1894. Sam Houston Jr., was buried in Independence, Texas, near his mother.