The military occupation of the Confederacy by the United States of America was a military occupation and guerrilla conflict that lasted between March of 1916 and December of 1921. The occupation was agreed upon as part of the terms of the Treaty of Lexington signed in 1916, and allowed for the stationing of American soldiers in the Confederate states of Arizona, New Mexico, Oklahoma, Kentucky, Tennessee and Virginia, as well as smaller deployments in strategic port cities such as New Orleans, Galveston, Norfolk and Savannah. The occupation existed ostensibly to protect the American border and ensure the transfer of shipping rights on the Mississippi River and through the Chesapeake Bay, major causes for the war between the USA and CSA.