Most of the bedrock in Puerto Rico consists of limestones and shales and young volcanic rocks. The island can be divided into three main parts: the coastal plains, the northern plateau and the Central Cordillera. The fertile coastal plains are partly bordered by sand dunes and are made up of alluvial deposits. Puerto Rico is located within the northern pass winds belt. San Juan has an average temperature of 24 °C in February and 27 °C in August. The rainfall is highest on the northern slopes, which can get about 4,000 mm of annual rainfall. The south coast, which lies in the shelter of the northeast passage, gets considerably less.
The island was originally covered by rainforest-like vegetation, which was heavily devastated during the 19th century. Wildlife is poor. Only native mammals are bats and rodents. Gold-spotted mangosteen, which was planted in 1877 to fight previously introduced black rats, has itself become a pest.
In 2016, Puerto Rico had a population density of 400 inhabitants per km2, and 71 percent of the population lived in cities, of which the metropolitan area of San Juan-Carolina-Caguas (2.2 million inhabitants, 2016) is the dominant one. More than 2 million Puerto Ricans live in the United States, most in New York. Puerto Ricans are US citizens with similar rights and obligations as mainland Americans. However, they do not participate in national elections and do not pay federal tax. Of the population, 99 percent are Spanish-speaking, and the cultural ties with Latin America are strong.
The Spanish colonial church founded a diocese as early as 1511. After the Spanish-American War of 1898, Protestant missionary societies from the United States gained a great influence. 85% of the population are Catholics and about 5% are Protestants. Methodists, Baptists, Presbyterians and Pentecostal friends. Ecumenical work between Catholics and Protestant churches is mostly done in the fight against poverty, against marginalization and for human rights. Large population groups practice Afro-Indian religious traditions and cults.
In 1493 Columbus visited Puerto Rico and named the island San Juan Bautista. The Spanish colonization began in 1508 under the leadership of Juan Ponce de León, who had the same year built the port that would later be called San Juan. The Native people who inhabited the island soon succumbed. During the 16th and 16th centuries, Puerto Rico was a poor colony with great strategic value.
During the latter half of the 18th century, Puerto Rico experienced a demographic upswing as the population more than tripled. Puerto Rico gained wide freedom of trade in 1815. Through a plantation system, based on slave labor until 1873, a profitable export of coffee, sugar and tobacco began. Puerto Rico remained under Spanish control until the Spanish-American War in 1898. The United States invaded the island in July 1898, and the same year Spain recognized the United States’ supremacy over Puerto Rico.
In 1917, the island gained limited self-government, and its inhabitants became American citizens. Puerto Rico was given the right to be elected governor in 1947, and in 1948 was elected leader of the Socialist Reformist PPD, Luis Muñoz Marín ( 1898–1980 ). Since 1952, when Puerto Rico gained its own constitution, the island’s political life has largely revolved around its relationship with the United States; see further Political conditions above. Extensive emigration to the United States, primarily New York, has taken place since the 1940s, but has been partially compensated for by relocation from the 1960s.
Referendums on the island’s political relationship with the United States were conducted in 1967, 1993, 1998 and 2012. Strong forces in Puerto Rico strive for the island to become a state in the United States, but in the referendums this line has not received enough strong support. In the 2012 referendum, the state line received just over 61 percent of the valid votes, but since just over a quarter voted blankly, the result was considered lacking sufficient legitimacy. A further referendum on the matter is to wait.