La Vallée has an extensive diaspora in the United States and Canada due to a substantial emigration beginning in the 1950s.

Father Bonnaud played a major part in the development of the area; he supervised construction of its first masonry buildings.

He also built the first dispensary, and restructured and enlarged the local open air market, one of the most important in the area.

La Vallée was a pioneer in the Haitian "cooperative movement" with the founding of the historic "Caisse Populaire" in 1946.

An association of locals created CODEVA in 1975, an organization that initiated many development projects, such as building the St Joseph hospital and the Lycée Philippe Jules.