* Many of the data on which this article is based were supplied by the Bureau of the Census from unpublished material. The author wishes to express his appreciation to the Census Bureau for making this material available. In addition to giving the author access to unpublished data, members of the Bureau's staff were very generous in giving advice and comments at various stages in the preparation of this work. Among those who were especially helpful are Henry S. Shryock, Jr., Henry D. Sheldon, and Richard A. Hornseth of the Population and Housing Division; and Joseph F. Daly and Leon Pritzker of the Office of the Assistant Director for Statistical Standards. At the same time that their help is acknowledged, it must be made clear that neither the Bureau of the Census nor any of the members of its staff in any way accepts, approves, or endorses the estimates herewith, presented.