Texas in the American Civil War

The American state of Texas declared its secession from the Union on February 1, 1861, and joined the Confederate States on March 2, 1861, after it had replaced its governor, Sam Houston, who had refused to take an oath of allegiance to the Confederacy. Houston had tried to forestall any steps the state might take towards secession but the State Legislature threw its support behind a secession convention, whose decision was approved by a statewide plebiscite overwhelmingly. No major battles or campaigns occurred in Texas during the Civil War, as compared to the rest of the South. The state instead supplied men (between 70,000 and 90,000) and material to the war effort. Troops from Texas saw service in every theater of the war, from the New Mexico territory to the eastern seaboard. Ports such as Galveston and cities along the Rio Grande such as Brownsville and Matamoros became the primary exporters of Southern cotton, bypassing the Union blockade.

Domestically the state government struggled to combat Indian raids on the frontier, opposition to conscription, and increasing banditry. Unionists, especially anti-slavery Germans in the Hill Country, endured severe violence over the course of the war at the hands of mob violence and many fled to the North or Mexico. Already underdeveloped at the beginning of the war, Texas' economy suffered a major collapse over the course of the war, including the exhaustion of its limited industrial capacity and railroads. Despite these issues the state successfully resisted Union invasion attempts, notably at Galveston and Sabine Pass, in 1863, and the war's final battle at Palmito Ranch, in 1865.

The social, political, and economic repercussions of the civil war significantly influenced Texas' development, especially under Reconstruction. Black Texans were freed in Texas on Juneteenth, and quickly became a major factor in state politics until their eventual disenfranchisement after the end of Reconstruction. Texas was readmitted to the Union on March 30, 1870. Before the war Texas had a population of 604,215, of which 182,566 were enslaved. By 1870 the state's population had increased to 818,579 including around 250,000 freemen, following the rise of cattle drives northward along routes like the Chisholm Trail. Cattle quickly became the dominant economic industry for remainder of the century.