Aces & Eights is set in an alternate history time line in which the American Civil War happened ten years earlier and the United Kingdom and France assisted the Confederate States of America (CSA). The Civil War lasted for ten years and both sides ground to a halt as resources and manpower started to run low for all concerned. The Republic of Texas never had a chance to join the Union and was neutral. With the Union tied up in a war of attrition with the CSA, the "Indian Territory", modern-day Oklahoma, was able to form their own government and withdrew from the Union. Mexico still owns much of the modern day western USA but does not have the manpower or money to govern it properly.