In the two decades after World War II, hundreds of thousands of Puerto Ricans boarded planes for America, in what has come to be known as the island’s “great migration.” Many farm workers, hastily flown north to help with harvests on the mainland, were transported in repurposed military cargo planes fitted with wooden benches or lawn chairs bolted to the floor. The vast majority of the island's émigrés bought tickets for the six-hour commercial flight to New York City, persuaded that good jobs and a better life awaited them and their families.

While some agricultural workers ultimately gravitated to cities near their farm assignments, about 85 percent of the island’s postwar émigrés—U.S. citizens, from a U.S. territory—settled in New York City, according to the Center for Puerto Rican Studies at the City University of New York. Between the 1940s and mid-1960s, this influx grew the city’s Puerto Rican population almost 13-fold, from 70,000 to nearly 900,000.

It was all part of a coordinated plan by the U.S. and Puerto Rican governments, which hoped to ease postwar labor shortages on the mainland while working to alleviate the territory’s crushing poverty.

The growing metropolis needed more workers after World War II, while farms across the Northeast and Midwest needed labor. Puerto Rico, meanwhile, couldn’t fully support its population. The island’s economic recovery plan, Operation Bootstrap, focused on shifting from an agrarian economy to an industrial one, leaving many workers out in the cold. The solution to both problems? Actively facilitate migration—and compel one-third of the population to head north.

“For all this to happen, migration is encouraged, sterilization is introduced in Puerto Rico to limit family size,” said Virginia Sánchez Korrol, a historian and professor at Brooklyn College, City University of New York, and author of From Colonia to Community: The History of Puerto Ricans in New York City. “And the U.S., particularly New York, begins to offer jobs.”

Puerto Rico became a U.S. territory after the Spanish-American War in 1898, when Spain ceded the island to the victorious United States. But Puerto Ricans’ lives worsened in the early decades of the 20th century after American sugar companies bought up farmland that had fed the local population. Instead, they began almost exclusively growing the cash crop of sugar cane for export to the U.S. market.

Islanders not only lost local food sources. Because sugar cane cultivation had a four-month-long off-season, scornfully known as tiempo muerto (“dead time”), workers’ wages nosedived. Families plunged into even more grueling poverty.

Keenly aware of the challenges workers faced in a single cash-crop economy, Puerto Rico’s first elected governor, Luis Muñoz Marín, campaigned in 1948 to give the island Commonwealth political status, which happened in 1952. With the United States’ help and approval, he developed the framework for Operation Bootstrap, designed to help better the lives of Puerto Ricans.

For a time, it was a rousing success. As the agrarian-based economy changed to a modern, industrial one, Puerto Rico's overall standard of living rose. American companies, enticed by generous tax incentives and a new pool of cheap labor, opened hundreds of factories on the island, producing everything from textiles and apparel to petrochemicals and pharmaceuticals. From 1954 to 1964, according to Sánchez Korrol, per capita income doubled, life expectancy rose by 10 years, school enrollments increased tremendously and birth rates declined by 5 percent.

But the new factories, along with the developing tourist economy, could not create enough jobs for everyone. The great migration became the safety valve to relieve the pressure.

Some 20,000 farmworkers hired as contract labor went to the Northeast and parts of the Midwest. Intense government campaigns, promising higher wages, inspired thousands every year to leave the countryside for the island’s cities and towns, and then to fly north. The Puerto Rican government actively facilitated this migration pattern by building out its air-transport infrastructure, stepping up English language education in the schools and facilitating farm work contracts on the mainland. Some émigrés made the trek alone to try their luck and send money to their families back home; others went and then sent for their families.

Puerto Rico’s seasoned needleworkers, who had made garments to counter German blockades of linens and clothing during World War I, were particularly sought after during the great migration. Seamstresses, many working independently at home, became the backbone of the island’s second-largest industry just before and during World War II. After 1945, new textile factories in Puerto Rico and in New York City’s bustling garment district avidly sought their labor.

In New York City, Puerto Ricans grew their communities. Bodegas (small grocery stores) and pirag__üeros (shaved ice vendors) popped up in neighborhoods now packed with the new arrivals working at factories, shipping docks and the garment district. Manhattan’s Spanish Harlem, called El Barrio, became the center of Puerto Rican business, entertainment and politics. Puerto Rican families also filled dilapidated tenement houses in the Lower East Side, called Loisaida, that Germans, Italians and Eastern European Jews had cleared out of.

The pressure on women to help make Puerto Rico’s economic recovery happen took some insidious turns. American and Puerto Rican economic development officials blamed “overpopulation” for the island’s grueling poverty. Social and health campaigns in the media, in schools and in birth control clinics stressed that having only two children and staying on the job was a path toward the middle class.

Postpartum sterilizations, known as ‘la operaci__ón’ or ‘the operation’, were legal, frequent and strongly encouraged during the postwar decades. And poor, uneducated Puerto Rican women were used as guinea pigs, critics say, in the first large-scale human tests in the 1950s of oral contraceptive pills.

In New York, the city’s political class and media, caught up in the growing battles over segregation and discrimination at the time, turned its collective gaze to the “Puerto Rican problem.” Echoing sentiments of the city’s elites, New York Mirror columnists Lee Mortimer and Jack Lait denounced in 1948 the “locust plague” of crude farmers “subject to congenital tropical disease.” They proclaimed Puerto Ricans “unskilled, uneducated, non-English speaking and almost impossible to assimilate in an active city of stone and steel.”

During the 1960s, the civil rights movement, with its loud clamor for racial and social justice, gave rise to a new generation of “Nuyoricans” who became the new forces of activism. Some 1,800 Puerto Ricans protested on the Brooklyn Bridge in 1964 demanding better education for their children.

The New York chapter of the Young Lords, a street gang turned civil and human rights organization, conducted mass education campaigns, promoted community empowerment and burned garbage on the streets in their “Garbage Offensive” in 1969 to protest substandard garbage collection service in El Barrio.

“You have all these kids questioning our social conditions in the United States and they began to take a more aggressive posture and a more assertive posture vis-à-vis the conditions they face,” said Carlos Vargas-Ramos, assistant director of development and external relations for the Center for Puerto Rican Studies at Hunter College.

Vargas-Ramos added, “They asked, ‘Why are we so hated? Why are we so poor?’ And they said, ‘No. We are not going to accept these conditions.’”