In 1863 the Union capture of Texas was viewed as crucial to the strategy to deny the Confederacy the territory west of the Mississippi and thus to break the back of Southern military force.

Overland, Texas supplied Louisiana and points east with needed goods; by way of Mexico, Texas offered a detour around the blockade of Southern ports and thus an economic link to England and France. But Union forces had no good base from which to interdict either part of the Texas trade. Their efforts were characterized by short, unsuccessful forays, primarily in East and South Texas. One of these, which left New Orleans on October 26, 1863, and was known as the Rio Grande Expedition, forms the centerpiece of this book.
Stephen A. Townsend carefully traces the actions—and inaction—of the Union forces from the capture of Brownsville by troops under Gen. Nathaniel P. Banks, through the advance up the coast with the help of Union Loyalists, until General Ulysses S. Grant ordered the abandonment of all of Texas except Brownsville in March 1864. Townsend analyzes the effects of the campaign on the local populace, the morale and good order of the two armies involved, U.S. diplomatic relations with France, the Texas cotton trade, and postwar politics in the state. He thoughtfully assesses the benefits and losses to the Northern war effort of this only sustained occupation of Texas.
No understanding of the Civil War west of the Mississippi—or its place in the Union strategy for the Deep South—will be complete without this informative study.