Beginning in 1821, President Jean Pierre Boyer, also an homme de couleur and successor to Pétion, managed to reunify the two parts of St. Domingue and extend control over the western part of the island.[30] In addition, after Santo Domingo declared its independence from Spain, Boyer sent forces in to take control. Boyer then ruled the entire island. Dominican historians have portrayed the period of the Haitian occupation (1822–42) as cruel and barbarous. During this time, however, Boyer also freed Santo Domingo's slaves.[31] During his presidency, Boyer tried to halt the downward trend of the economy by passing the Code Rural. Its provisions sought to tie the peasant labourers to plantation land by denying them the right to leave the land, enter the towns, or start farms or shops of their own.[32]

During Boyer's administration, his government negotiated with Loring D. Dewey, an agent of the American Colonization Society (ACS), to encourage free blacks from the United States (US) to emigrate to Haiti. They hoped to gain people with skills to contribute to the independent nation. In the early 19th century, the ACS – an uneasy blend of abolitionists and slaveholders – proposed resettlement of American free blacks to other countries, primarily to a colony in Liberia, as a solution to problems of racism in the US. Starting in September 1824, more than 6,000 American free blacks migrated to Haiti, with transportation paid by the ACS.[33] Due to the poverty and other difficult conditions there, many returned to the US within a short time.

In July 1825, King Charles X of France sent a fleet of 14 vessels and thousands of troops to reconquer the island. Under pressure, President Boyer agreed to a treaty by which France formally recognized the independence of the nation in exchange for a payment of 150 million francs (reduced to 90 million in 1838) – an indemnity for profits lost from the slave trade. French abolitionist Victor Schoelcher wrote, "Imposing an indemnity on the victorious slaves was equivalent to making them pay with money that which they had already paid with their blood."

After losing the support of Haiti's elite, Boyer was ousted in 1843. A long succession of coups followed his departure to exile. In its 200-year history, Haiti has suffered 32 coups; the instability of government and society has hampered its progress.[34] National authority was disputed by factions of the army, the elite class, and the growing commercial class, increasingly made up of numerous immigrant businessmen: Germans, Americans, French and English. In 1912, Syrians residing in Haiti participated in a plot in which the Presidential Palace was destroyed. On more than one occasion, French, US, German and British forces allegedly claimed large sums of money from the vaults of the National Bank of Haiti.[35] Expatriates bankrolled and armed opposing groups.[citation needed]

For this reason, the United States refused for nearly six decades even to recognize Haiti. (Abraham Lincoln finally did so in 1862.) Along with the great colonial powers, America instead rewarded Haiti’s triumphant slaves with a suffocating trade embargo — and a demand that in exchange for peace the fledgling country pay enormous reparations to its former colonial overseer. Having won their freedom by force of arms, Haiti’s former slaves would be made to purchase it with treasure.