In 1865, Confederate cotton from blockaded states streamed into the Rio Grande Valley throughout the war, and from Brownsville it could be smuggled across or down the river for sale to international buyers. At the time of the Palmito Ranch fight, Brownsville warehouses held about 2,000 bales of cotton awaiting buyers across the border in Matamoros, Mexico. Union forces on the coast, knowing that Confederate troops had already surrendered in the east, may have marched inland hoping to seize one last cache of Brownsville cotton for the Union as the Confederacy collapsed. The Rio Grande once flowed deep enough to support dozens of steamboats carrying passengers, troops, and goods, but after the Civil War the river and its wetlands began losing water to irrigation upstream, and by the early 1900s even shallow-draft flatboats could no longer navigate it. Wartime cotton prices rose from 16 cents to $1.25 a pound, while the Civil War-era cotton economy exacted a human cost in the thousands of men, women, and children held as slaves.