This section presents summary economic and social statistics for Puerto Rico, Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands. Primary sources are the decennial censuses of population and housing and the censuses of agriculture, business, manufactures, and construction (taken every 5 years) conducted by the U.S. Census Bureau; the annual Vital Statistics of the United States, issuedby the National Center for Health Statistics; and the annual Income and Product of the Puerto Rico Planning Board, San Juan.

Jurisdiction-The United States gained jurisdiction over these areas as follows: The islands of Puerto Rico and Guam, surrendered by Spain to the United States in October 1898, were ceded to the United States by the Treaty of Paris, ratified in 1899. Puerto Rico became a commonwealth on July 25, 1952, thereby achieving a high degree of local autonomy under its own constitution. The VirginIslands, comprising 50 islands and cays, was purchased by the United States from Denmark in 1917. American Samoa, agroup of seven islands, was acquired by the United States in accordance with a convention among the United States, Great Britain, and Germany, ratified in 1900 (Swains Island was annexed in 1925). By an agreement approved by the Security Council and the United States, the Northern Mariana Islands, previously under Japanese mandate, was administered by the United States between 1947 and 1986 under the United Nations trusteeship system. The Northern Mariana Islands became a commonwealth in 1986.

Censuses-Because characteristics of the outlying areas differ, the presentation of census data for them is not uniform. The 1960 Census of Population covered all of the places listed above except the Northern Mariana Islands (their census was conducted in April 1958 by the Office of the High Commissioner), while the 1960 Census of Housing also excluded American Samoa. The 1970, 1980, and 1990 Censuses of Population and Housing covered all five areas. The 1959, 1969, and 1978 Censuses of Agriculture covered Puerto Rico, American Samoa, Guam, and the Virgin Islands; the 1964, 1974, and 1982 censuses covered the same areas except American Samoa; and the 1969, 1978, 1987, 1992, and 1997 censuses included the Northern Mariana Islands. Beginning in 1967, Congress authorized the economic censuses, to be taken at 5-year intervals, for years ending in ‘‘2’’ and ‘‘7.’’ Prior economic censuses were conducted in Puerto Rico for 1949, 1954, 1958, and 1963 and in Guam and the Virgin Islands for 1958 and 1963. In 1967, the census of construction industries was added for the first time in Puerto Rico; in 1972, Virgin Islands and Guam were covered. For 1982, 1987, 1992, and 1997 the economic censuses covered the Northern Mariana Islands.

Information in other sections-Inaddition to the statistics presented in this section, other data are included as integral parts of many tables showing distribution by states in various sections of the Abstract. See ‘‘Outlying areas of the United States’’ in the Index. For definition and explanation of terms used, see Section 1, Population; Section 4, Education; Section 17, Agriculture; Section 20, Construction and Housing; Section 21, Manufactures; and Section 22, Domestic Trade.