Haiti was the first autonomous nation in the Americas to abolish slavery in it's Constitution of 1801.

However, slavery had been abolished in all French holdings in 1794 under Robspierre (although later re-imposed) This means not just abolition in Haiti but the other French holdings in the Americas. So this included the vast swathe of land reaching from Canada to Lousiana, their Caribbean holdings, as well as French Guiana in South America.. The extent this was just a de-jure emancipation and reflected any greater degree of freedom being granted in real terms varied hugely across the French Colonial Empire.