In the 1940s and 1950s, migration from Puerto Rico to the mainland surged as a result of Operation Bootstrap, a federal program aimed at industrializing Puerto Rico’s agricultural economy. For Operation Bootstrap to be successful, at least one million Puerto Ricans would have to relocate, prompting the largest airborne migration in U.S. history. In a photograph taken in 1946, a woman is shown carrying a young boy while waiting to board a plane from San Juan to New York City.