Population Profile of the United States: 1999 5
U.S. Census Bureau
ALL ACROSS THE USA:
Population Distribution, 1999
the United States and where they live. In the interim,
people are born and die; some move away and others
take their place. For the years in between censuses,
people who need more recent numbers rely on
intercensal population estimates from the U.S. Census
Bureau. Among other things, the estimates are used
to allocate federal funds and monitor recent popula-
How many people live in
the United States and where
do they live? The answers to these
questions are constantly changing.
In years ending in zero, population censuses provide
detailed information about the number of people in
Words That Count
• Population estimates, as produced by the U.S.
Census Bureau’s Population Estimates Program, are
approximations of populations for past dates. The
calculations begin with the last census numbers
and then are updated using data on births, deaths,
and migration. Estimates of external and internal
population movement are developed from tax re-
turns, Medicare enrollment, and immigration data.
The population estimates in this report are based
on the 1990 census. The numbers in this report
cover the 50 states and the District of Columbia,
but do not include any of the U.S. outlying areas,
such as Puerto Rico, the U.S. Virgin Islands, Guam,
American Samoa, or the Commonwealth of the
Northern Mariana Islands.
• Resident population includes all people living in
the United States.
• Civilian noninstitutional population is the ba-
sic universe for the Census Bureau surveys used in
this report, the Current Population Survey (CPS),1
the Survey of Income and Program Participation
(SIPP), and the American Housing Survey (AHS). It
includes everyone who is not in an institution and
is not in the military.
• The four statistical regions of the United
States are groups of states for which data are
presented. They include the Northeast, the Mid-
west, the South, and the West. See map on page 13.