The U.S. population grew 9.7 percent in the past decade — the lowest rate since 1930-40, according to the first results of the 2010 decennial census released today.
The U.S. Constitution mandates that the census be conducted every 10 years in order to redistribute seats in the U.S. House of Representatives proportionally by population. Census figures also allow businesses to gauge new markets and determine the distribution of funds for several federal programs including health care, education, and unemployment insurance.
Source: U.S. Census Bureau
The official count for the U.S. resident population as of April 1, 2010 was 308,745,538, up from 281,421,906 in 2000.
Put in a historical context, the nation had a population of 3.9 million at the time of the first census in 1790. By 1910, that population had risen to 92.2 million and grew at a double-digit rate nearly every decade after that.
The exceptions were: between 1930 and 1940 when the population grew by 7.3 percent to a total of 132.2 million; between 1980 and 1990 when the population grew 9.8 percent to 248.7 million; and this past decade, between 2000 and 2010, when it grew 9.7 percent to 308.7 million.
Source: U.S. Census Bureau
Robert M. Goves, the director of the U.S. Census Bureau who presented the findings, declined to speculate as to the reasons behind any population changes, saying that would be the work of demographers for years to come.
Teasing out the effect on population of the most recent recession or the Great Depression from all the other things happening during those periods would be difficult, he said.
He also added that the smaller growth rate could be part of a broader trend for countries worldwide, whose populations have also been growing more slowly.
In terms of whether "natural increase" (fertility) drove the rise, or immigration, he said, "Based on our demographic analysis, 60 percent of the growth (in the past decade) was due to natural increase and 40 percent was due to immigration."
Regionally, the Northeast saw the smallest growth rate, 3.2 percent, followed by the Midwest at 3.9 percent. The West grew by 13.8 percent, while the South, the nation’s most populated region, had the highest growth rate, 14.3 percent.
In terms of state population, Nevada grew the most in the last decade, up 35.1 percent, to 2.7 million. Michigan was the only state to see a decline, 0.6 percent to 9.9. million, while the territory of Puerto Rico saw a 2.2 percent decrease, to 3.7 million.
Rate of change in population (2000-10):
The five most populous states as of April 1, 2010 were California, Texas, New York, Florida and Illinois. The least populous states were Wyoming, Vermont, North Dakota, Alaska, and South Dakota.
Michigan, Rhode Island, Louisiana, Ohio, and New York had the slowest growth rates between 2000 and 2010.
New Jersey, Rhode Island, Massachusetts, Connecticut, and Maryland — all part of the original 13 states — have had the highest population density for the past 40 years. Alaska, Wyoming, Montana, North Dakota, and South Dakota have had the lowest population density for the past 20 years.
As a result of this year’s census results, 12 U.S. House seats have shifted, impacting 18 states. Texas, whose population rose 20.6 percent to 25.1 million, gained four seats. Florida gained two after a 17.6 percent rise in population, to 18.8 million. Washington, Nevada, Utah, Arizona, Georgia and South Carolina each saw double-digit gains in population and each gained one seat.
Source: U.S. Census Bureau
Ohio and New York each lost two seats. Iowa, Illinois, Missouri, Michigan, Massachusetts, New Jersey, Pennsylvania and Louisiana each lost one seat. The remaining 32 states saw no change. Each state is guaranteed at least one representative.
Since 1940, the Northeast and Midwest have lost 79 seats in the House to the West and the South.
As of this count, California has the most seats, 53, followed by Texas, 36, and then Florida and New York, each with 27. Each seat will now represent an average of 710,767 persons, up from 646,952 persons in 2000.
"The decennial count has been the basis for our representative form of government since 1790," Groves said in a statement. "At that time, each member of the House represented about 34,000 residents. Since then, the House has more than quadrupled in size, with each member now representing about 21 times as many constituents."
States can begin the redistricting process after next spring when the bureau releases population figures down to the block level starting in February through March 31, 2011. The bureau will also release demographic data, including race and housing occupancy status, at that time.
