Modern Puerto Rico is generally well-off by Latin-American standards. Beginning in the 1940s, a political coalition between the Puerto Rican leader Luis Muñoz Marín and the U.S.-appointed governor, Rexford Guy Tugwell, was forged to promote a self-help program, called “Operation Bootstrap,” of economic development and social welfare. In a little more than four decades, much of the territory's crushing poverty was eliminated. This was done partly through emphasis on the development of manufacturing and service industries, the latter related to an enormous growth in tourism. Improvements have been made largely with the cooperation of the United States, but relationships with that nation have also become a focal point of political turmoil. Various factions have bitterly disputed the political status of the island, and, although a majority voted to retain its commonwealth relationships, strong minorities have continued to push for statehood or—at times with violence—freedom.

Puerto Rico’s Spanish heritage is preserved in many sites in San Juan, particularly in the insular part of the city known as Old San Juan. Among these sites are the El Morro and San Cristóbal fortresses, both part of San Juan National Historic Site; La Fortaleza, once a fortress and now the governor’s palace, its oldest section completed in 1540; Old Santo Domingo Convent, built between 1523 and 1528; and Fort San Gerónimo, completed in the late 18th century.