A good article might be: Girard, Philippe R. "Caribbean genocide: racial war in Haiti, 1802–4." Patterns of Prejudice 39.2 (2005): 138-161.

Obligatory I'm not a historian but I do research in Haiti and I also have access to this article. So I can happily share the main points of the article and hopefully that helps answer some of your question.

Girard's article starts out quoting some of the Haitian Revolution leaders and their attitudes about their goals. They weren't just looking for justice or freedom. They quite openly wanted vengeance. Remember most enslaved peoples in Haiti were born in Africa. They vividly remembered being sold, chained across the ocean, and being enslaved in one of the most brutal slave systems in the New World. For example,

Louis Boisrond-Tonnerre complained that the first draft of the declaration of independence was not aggressive enough, saying that ‘we should use the skin of a white man as a parchment, his skull as an inkwell, his blood for ink, and a bayonet for a pen"

And Jean-Jacques Dessalines (probably one of the most famous revolutionary leaders at least by contemporary Haitian standards) said to his troops:

. Let us frighten all those who would dare to steal our freedom; let us start with the French! May they shudder when they approach our coastline, either because they remember all the exactions they committed, or because of our horrifying pledge to kill every Frenchman who soils the land of freedom with his sacrilegious presence.

And Girard shows that this was not an empty threat.

Over the following four months, on Dessalines’s orders, soldiers rounded up white planters, their families, French soldiers and the urban poor known as petits blancs, and killed them. Neither women nor children were spared.

Dessalines had originally told some petit blanc that they would be spared. But they were also killed and many women brutally raped. Dessaline's 1805 constitution did allow some widows to survive as well as some Germans and Poles who had defected from the French army. But in becoming Haitian they also legally became black. This is a category that still exists today - all Haitians are either mulat or neg (mulatto or black). Foreigners are all blan (white) even if they would be considered black in the US.

Anyway, Dessalines made it very clear that his intent was in line with what we'd define as intent to commit genocide. And he did not hide it from outside eyes.

In Port-au-Prince, Frenchmen were dressed as if for a funeral, ‘paraded through the streets in great fanfare, then drowned in the port’ in full view of British and American ships.13 A copy of Dessalines’s vengeful independence day proclamation was even sent to the Gazette of Philadelphia. 14 In April 1804 Dessalines proudly announced that the genocide was then consummated. ‘The implacable enemies of the rights of man have finally met a punishment worthy of their crimes.’

The second part of the definition of genocide is that it is large scale with the intent to remove a particular group from society. There is some debate about how many people were actually killed by Dessalines who weren't soldiers but the numbers are somewhere around 30,000 total over the entire period of the war (including displaced and therefore unaccounted for whites.) In contrast, 50,000 French soldiers lost their lives in 1802-3 alone. So some have argued it doesn't count as genocide because it was in no way a threat to the survival of French people. However, Girard disagrees because the point was that they were exterminated from Haitian society.

Girard then gets to one of your questions - why? And why then?

Dessalines offered a military explanation (killing all Whites would forever scare away potential invaders) that was far from convincing. The genocide took place after the last French troops surrendered. Some battered remnants of the French expeditionary force regrouped in Cuba and Santo Domingo, but they were too small to go on the offensive and the resumption of France’s war with England made further reinforcements impossible. If anything, horror at Dessalines’s cruelty could have prompted France to summon another expedition to avenge the dead. Economically, the genocide also exterminated planters who, for all their faults, were the most educated and entrepreneurial members of Haiti’s population. By the 1820s the large sugar plantations had been divided into small lots cultivated by illiterate subsistence farmers. The shift pleased the former slaves immensely, but it shattered Dessalines’s hopes for large-scale agriculture.

Dessalines' speeches and some letters from the French suggest a few reasons more compelling than being scary. First, there was the rights of man and ideals that motivated people to fight and die for. The French Revolution inspired Haitian revolutionaries. Second, the French committed some horrible acts during the war (and before) and this motivated a need for vengeance. Third, it had been 13 years and he needed to do something that would just end the fighting once and for all. A radical move that there would be no coming back from. Fourth, racism that leads to a dehumanization of blacks also works conversely - the oppressors become dehumanized too. And lastly, there was a hope that they could just step into the plantations and shops the whites had owned and take over.

Another important point is what happened in 1802 to Louverture. Things had finally calmed and it looked like they were moving towards independence without further violence. Louverture ruled Haiti and wasn't always 100% popular, but the peace was popular. Then Napoleon's brother-in-law General Charles Leclerc showed up. He said he was just sending reinforcements for the black troops but Louverture thought this was shady. So he instructed his troops to fire upon them. The black Haitian troops lost but they set fire to things on their way out.

A very bloody war started up again and over the next 18 months over 50,000 of Leclerc's men died. Both sides committed atrocities and slaughtered huge groups of civilians. And then, of course, there was the event where a bunch of Haitian leaders (Dessalines included) supported the French capture of Louverture leaving an opening for figures like Dessalines to take over. When the French got rid of Louverture they also got rid of a ruler who had kept white advisors and believed that mass slaughter was not the solution.

Yellow fever hit the French troops hard right about then killing devastating numbers. Dessalines later took credit saying Haiti had sent the illness.

For the French side, this experience as well as the desperation to take back the richest colony led to some horrific acts.

French soldiers resorted to methods deemed unacceptable in the European theatre, including such tortures as burning and breaking at the wheel that were by then illegal in France.49 Blacks were gassed in the hold of ships or thrown overboard, a practice one captain referred to as ‘mettre de la morue a` la trempe’ (giving codfish a bath).50 Rochambeau even imported 200 slavehunting dogs from Cuba.51 To test this new weapon, or to fulfil some sadistic fantasy, he ordered an arena built in which the dogs devoured a black man. All the leading members of Cap Franc¸ais society attended, as if this were a gladiator fight in a decadent Rome.

Dessalines referenced these acts and the mass killings of blacks in general during his speeches. Leclerc also argued for mass killings in his own letters. In 1802 he wrote to Napoleon,

We must destroy all the Negroes in the mountains, men and women, keeping only infants less than twelve years old; we must also destroy half those of the plain, and leave in the colony not a single man of color who has worn an epaulette. Without this the colony will never be quiet.

Leclerc died in 1802 and Donatien Rochambeau took over, who also liked killing black people as part of the larger plan.

7 Indeed, it might seem counter-intuitive to exterminate the entire black population when slaves were the backbone of Haiti’s plantation economy. But, Leclerc argued, Blacks were so corrupted by freedom that they could never be reenslaved. It was safer, despite the human and financial cost, to kill them all and import a new batch of slaves from Africa

So it is important to note that it wasn't just the black Haitians who were looking to exterminate whites. French military leaders were looking to do the same thing to them. But thinking about it as a racially based thing is probably too simplistic. Remember that under the French there were three racial categories and they were more fluid than we usually think about race. The Haitian revolution is incredibly complicated in part because it seems like everyone at some point was fighting everyone else. And, in many ways, it was more about class and capitalism than race, though I do not want to downplay the incredible racism inherent in the institution of slavery. But it isn't simply race wars. It was about those who owned people - which some mulattos and free people of color did - vs those who were owned. It was about colonialism and disenfranchisement. And it was the outcome of an incredibly violent and lengthy war.

Ok, I am majoring in International Law, and am VERY strict personally with what IS or IS not an act, acts, or period defining genocide under international law.

First you must look at the definition under the Convention on the Prevention and Punishment of the Crime of Genocide; Genocide means any of the following acts, committed during war of peace, committed with the intent to destroy in whole or in part, an ethnic, racial, religious and/or national group through the following;

A) Killing members of the group B) Causing Serious Bodily or Mental harm C) Deliberate infliction of conditions calculated to destroy the group E)Attempts to prevent births within the group , I left out D) as transferring children from one to another is an act, but doesn't appear to have occurred or at least constituted any of the specifically intended acts...

In short, yes, in my opinion very clearly. You HAVE to be careful as neo-Nazis and white supremacist do use this event to justify insane and insidious claims of modern "white genocide", or equate the oppression of slavery to the tragic but significant event in Haiti. Genocide is a hard crime to prove requiring specific intent to PHYSICALLY or BIOLOGICALLY destroy in whole or in (substantial) part... The "substantial" element was cited in the Appeals case of Prosecutor V. Radislav Krstic in the ICTY regarding the genocide in Srebrenica (Eastern Bosnia) in July of 1995, which targeted 40,000 Bosnian-Muslims isolated in the "safe areas" of Srebrenica and Zepa through killing of 8,000 men and boys and transfer and abuse of women and some children and elderly. Amounting to 1-2% of the total Muslim populace but a substantial geographic area and a shockingly organized and fast paced murder and cleansing operation.

The Krstic appeals chamber made clear that the numeric size of the targeted group "is the necessary starting point but not ending point", "the number of targeted members must be assessed in relation to the overall size of the entire group." When assessing the size of the group, Dessalines targeted the ENTIRE FRENCH CREOLE (not simply white, a specific ethnic group that was white) populace. In Rwanda this amounted clearly to genocide. When groups are physically or biologically targeted for destruction in whole, it's organized nature, the end result and methods are assessed to determine the qualifications. When you hear a number of 30,000 etc...I would be VERY questioning of such claims as this is the TOTAL number of those who died DUE to WAR. If the specific intent, the organization and sizable portion of a group (once again to cite the Krstic case, a size large enough to have an affect on the group as a whole), qualifies then yes, it may be genocide. The actions of several French commanders targeted a large number of innocent individuals for death (Extermination under modern intl law). It's difficult to know the number of black people who lived in haiti and the organization and size of the individuals targeted, but other acts of genocide MAY have been carried out...perhaps not. However the deliberate destruction of the white populace of Creole ethnicity of Haiti, (using silent weapons to kill as many as quickly as possible, using direct and public incitement to result in a desire for revenge amongst civilians, the preperations and EXPLICIT goals of the murder operation and its completing in 2-3 months (if we say, conclude 4,000 were killed), if the event was deliberately large enough to affect the entire group in some way, it may qualify. Based on the fact the entire FRENCH CREOLE, not white population solely.

I can see few other events that in my opinion qualify as genocide...as clearly, the simple fact millions don't exist, doesn't mean they can't be rendered extinct. (Darfur indictment and the Srebrenica conclusions confirm this), however to assess events hundreds of years ago, and impuning Intl law, is difficult. If looked at "on its face" (prime facie), it clearly meets the terms defining genocide. However exaggerating numbers over 6,000 as some do, or claiming it was targeting "white people", and not French Creoles, is disingenuous, as well as we don't know clearly all events that occurred during that war, however the events of early 1804...pretty convincingly, I would bet my bank account would be ruled as genocide under modern intl law. Again not to, make ANY of the acts of enslavement and extermination justified, crimes are crimes if they meet the definition of the actus Reus and mens rea, (this does both).