John Carter of Mars is Civil War revisionism at its worst
John Carter gets the Overthinking It treatment, to great effect.
Sic Semper Zodanga: John Carter and the War of Martian Aggression | Overthinking It

John Carter is from Virginia. He fought for the Confederacy in the Civil War. It was Union soldiers that slaughtered his family; Union soldiers are presented as the first villains in the narrative as they try to force Carter to join them in some old-fashioned, Yankee-style Indian killing.
The real story of John Carter is an alternate history of the Civil War from the Confederate point of view. John Carter is transported into the midst of another conflict between cultures. Defeat means forced union, a loss of tradition, the eventual death of civilization. But this time, with John Carter’s help, the ‘South’ wins.
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The Civil War allegory on Mars is fairly straightforward. Helium represents the Confederacy and Zodanga the Union. This is evident before we even get to the plot, just through what we learn about their cultures. Helium is a shining city on a hill (on a pillar over the edge of a cliff, to be exact), led by an aristocracy of honourable, gods-fearing warrior-poets who live, literally, in an ivory tower. Even the name of the city evokes a light-hearted buoyancy, an ability to rise above everyday troubles. Appropriately, we never see the common people of Helium, the ones that toil in the red Martian dirt to feed, clothe, and arm the Helium elite. Zodanga, by contrast, is a gritty, crowded, industrialized place. It is literally impossible for anyone in Zodanga to ever put down roots, as the city is always on the move, creeping across the land.
Helium is firmly bound to the land yet rises above it; Zodanga has no land but what it destroys in passing, yet can’t escape wallowing in the dust. This reflects how the Confederate plantation owners and other aristocracy viewed themselves and their urbanized Northern opponents in the run-up to the war.
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