When the war between the states began in 1861, Millican was Texas' northernmost railroad terminus and became a vital Confederate shipping point for the region reaching north to the Red River and west to the frontier settlements. Products from that area moved over the Houston and Texas Central Railroad from Millican to Houston, Beaumont, Galveston, and Alleyton. Confederate troops came by rail to nearby Camp Speight, a training and rendezvous point; many marched overland from Millican for duty in Arkansas and Louisiana, while others entrained for Houston and Beaumont to board ships for Neblett's Landing on the Sabine and other debarkation points. During the war, cotton from North Texas and the Brazos Valley went to market through Millican to Alleyton, the state's southernmost railroad terminus, where wagons and carts carried it over the cotton road to Brownsville and Matamoros, Mexico. Returning wagons and carts brought military supplies and merchandise, which eventually reached Millican by rail for wide distribution. Born with the coming of the railroad in 1859, Millican flourished with the railroad and declined after its northward extension began in 1866.