Thomas Green was an American soldier and lawyer, who took part in the Texan Revolution of 1835–36, serving under Sam Houston, who rewarded him with a land grant. Green was clerk of the Texas Supreme Court until the outbreak of the Civil War, when he became a Confederate cavalry leader. After winning several victories, including the Battle of Valverde and the recapture of Galveston, he was promoted brigadier and assigned command of the cavalry division of the Trans-Mississippi Department. In the Red River Campaign, he was mortally wounded while charging a fleet of Federal gunboats. The Union naval commander David Dixon Porter paid tribute to Green as a serious loss to the Confederacy.

The Red River campaign, also known as the Red River expedition, was a major Union offensive campaign in the Trans-Mississippi theater of the American Civil War, which took place from March 10 to May 22, 1864. It was launched through the densely forested gulf coastal plain region between the Red River Valley and central Arkansas towards the end of the war. The offensive was intended to stop Confederate use of the Louisiana port of Shreveport, open an outlet for the sugar and cotton of northern Louisiana, and to split the Confederate lines, allowing the Union to encircle and destroy the Confederate military forces in Louisiana and southern Arkansas. It marked the last major offensive attempted by the Union in the Trans-Mississippi Theater.