A combination of the Great Depression of the 1930s, the end of prohibition, and World War II severely dampened Cuba's tourist industry, and it wasn't until the 1950s that numbers began to return to the island in any significant force. During this period, American organized crime came to dominate the leisure and tourist industries, a modus operandi outlined at the infamous Havana Conference of 1946. By the mid-1950s Havana became one of the main markets and the favourite route for the narcotics trade to the United States.