 It was re-established as the capital of all of Haiti when the country was unified again in 1820.During the American occupation of Haiti (1915–1934), Port-au-Prince, garrisoned by American Marines and Haitian gendarmes, was attacked twice by caco rebels.The first battle, which took place in 1919, was a victory of the American and Haitian government forces, as was the second attack in 1920.