The revisions in and additions to the list of standard metropolitan statistical areas (SMSA's) announced on October 18, 1963, by the Bureau of the Budget gave metropolitan classification to territory with a 1960 population of 2.9 million. This increase brought the 1960 population of the 216 SMSA's in the United States to 115.8 million, or nearly two-thirds of the population of the country as a whole (table 1). Four new areas were established, and the definitions of 57 areas were revised. The new areas are Anaheim–Santa Ana-Garden Grove, California; Vallejo-Napa, California; Boise City, Idaho; and Lafayette, Louisiana. The first two areas resulted from the division of the Los Angeles-Long Beach and San Francisco-Oakland areas, respectively. The Boise City and Lafayette areas were recognized because the Bureau of the Census has found that the population of these cities has passed the 50,000 mark since the 1960 Census. No county or town classified as metropolitan for the 1960 Census is classified nonmetropolitan on the basis of the new definitions.

The additions to the SMSA's as shown in the reports of the 1960 Census of Population consist of 64 counties and, in the New England States, 37 towns. These areas had a combined 1960 population of 2,909,831 as compared with 2,251,210 in 1950. The rate of increase for these areas between 1950 and 1960 (29.3 percent) was somewhat greater than for the areas as previously defined (26.4 percent) and nearly five times as rapid as the rate of growth in the nonmetropolitan areas (6.3 percent).