Dixie posits an alternate history where the Southern filibuster William Walker, as president of Nicaragua, chose to protect Cornelius Vanderbilt's Accessory Transit Company rather than turn on his tycoon supporter. Without Vanderbilt's opposition to his regime in this timeline, Walker was able to conquer Cuba and make his Nicaragua the most powerful nation in Latin America. During the American Civil War, Walker's ships ran the Union blockade and ensured that Southern troops were well-supplied, leading to their victory over Northern forces and the independence of the Confederate States of America.
The "current year" in Dixie is 1985, with the world dominated by the U.S.A., C.S.A., the German Second Empire, the Russian Soviet Republic, and the United Republic of India.