1 - Introduction

Abstract

For any given urban area, population growth must originate from one or more of the following sources: (1) reclassification of previously nonurban population, (2) natural growth, and (3) net in-migration. Historically, relatively little urban population growth has been a result of spatial reclassification of existing population. As urban areas have grown and encompassed more land, substantial growth has occurred in the spatial areas that had been classified as nonurban during the past. The distinction here is between absorbing an existing population into an urban area through reclassification and absorbing a land area in which subsequent population growth occurs. Data are usually sufficient to distinguish reclassification as a source of urban population and employment growth. This chapter focuses on the period following World War II, especially on the period from 1950 to 1970. The chapter presents a table that reports the population of the United States as enumerated in each census from 1790 to 1970. This table also reports the regional distribution of the U.S. population. The postwar period is characterized by considerable regional diversity in the urbanization process. The urbanization occurred at a rapid pace in the South and at only a slightly lower pace in the West; however, the North Central region experienced only a modest increase and the Northeast almost none.