There is absolutely no reason why Haiti should've been allowed to secede from France and become independent.
Ca. 1697--1794, Haiti became
prosperous as a
plantation colony of
France, based on black slavery (presumably similar to the U.S. South). By 1795, on the whole island
Española, black slaves outnumbered whites 12
1/
2-to-1.
Presumably inspired by overseas news of the early days of the
French Revolution--"
liberté, egalité"--Haitian blacks revolted in 1794, promoted with a goal of gaining "
equal rights" (or somesuch), but the independence they sought for themselves was via
secession.
A decade or so later, Napoleon sent a large
French army to Haiti to
crush the rebellion, but they suffered a thorough
defeat (1804) [†]. Altho' at least 1 of the slave-rebel leaders, Toussaint L'Ouverture, Jean-Jacques Dessalines, or Henri Christophe, was credited with being a surprisingly effective (self-taught?) field general, their inexperienced slave-rebel troops weren't the main reason for the defeat of the French. Substantially more French casualties were caused by cases of
yellow fever.
But all the Haitians lived happily ever after. White Haitians who failed to flee the island (e.g., to New Orleans, sometimes accompanied by loyal slaves) were
killed by the black rebels [×]. They don' wan'
no steen-keen "
fraternité"! Readers unafraid of being smeared as "racist" might call that Haiti's "
Final Solution", because it was at least
de facto genocide of whites by the black former slaves.
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Note †: My summary-style source is ambiguous about whether its "1804, Jan. 1" was the date of Napoleon's order or his army's surrender in Haiti.
Note ×: I have not incorporated any content from Wikipedia, which I fear might have been bludgeoned into inaccuracies or omissions for the sake of political correctness, esp. the genocide of whites by the black former slaves. I admit that cursory review of Wikipedia seems not to be as biased as I feared, but its dates are sometimes different from my source, even in terms of the years given. Those that differ are not off by much, but maybe I'll try to resolve the differences after I post this.