While acknowledging the cross-influences, most contemporary historians distinguish the Haitian Revolution from the French Revolution. Some also separate it from the earlier armed conflicts by free men of color who were seeking expansion of political rights for themselves, but not the abolition of slavery. These scholars show that if the agency of the enslaved blacks becomes the focus of studies, the Revolution's opening and closing dates are certain. From this premise, the narrative began with the enslaved blacks' bid for freedom through armed struggle and concluded with their victory over slavery powers and the creation of an independent state. In April 1791, a massive black insurgency in the north of the island rose violently against the plantation system, setting a precedent of resistance to racial slavery. In cooperation with their former mulatto rivals, blacks ended the Revolution in November 1803 when they decidedly defeated the French army at the Battle of Vertières. The French had already lost a high proportion of their troops to yellow fever and other diseases. After acknowledging defeat in Saint-Domingue, Napoleon withdrew from North America, agreeing to the Louisiana Purchase by the United States.