Over the past decade, the U.S. population grew at the second slowest rate since the government started counting in 1790, the Census Bureau reported Monday, a remarkable slackening that was driven by a slowdown in immigration and a declining birthrate.

The bureau also reported changes to the nation’s political map: The long-running trend of the South and the West gaining population — and the congressional representation that comes with it — at the expense of the Northeast and the Midwest, continued, with Texas gaining two seats and Florida one, and New York and Ohio losing. California, long a leader in population growth, lost a seat for the first time in history.

The data will be used to reapportion seats in Congress, and, in turn, the Electoral College, based on new state population counts. The count is critical for billions of dollars in federal funding as well as state and local planning around everything from schools to housing to hospitals.

The numbers are the product of the most embattled census process in decades. The Trump administration tried — and failed — to have a citizenship question added to the Census form and to have unauthorized immigrants removed from the count.The Census Bureau also faced a daunting task of conducting the census during a pandemic. Then, last summer, the Trump administration pushed it to stop the count sooner than planned, leading to a long court fight.

At a news conference Monday, Gina Raimondo, the U.S. secretary of commerce, declared the count to be “complete and accurate,” but questions and potential challenges to the data will most likely surface when the Census Bureau releases the detailed demographic files for each state later this year. Those files, due out by Sept. 30, are the basis for redrawing electoral districts, a messy political process that is fought in statehouses across the country.

The population shift to the Sunbelt has been happening for years but its political meaning is changing. In decades past, Sunbelt gains often translated to automatic plusses for Republicans in the Electoral College. Now the calculus is more complicated with political competition increasing in more states.


While Donald Trump won the four fastest-growing states — Utah, Idaho, Texas and North Dakota — President Joe Biden won four of the next five on the list: Nevada, Colorado, Washington and Arizona.

Regardless of which party ultimately benefits, the findings appear to solidify a gathering pattern in American life: The South and the West are increasingly the centers of population and power, surging ahead of the Northeast and Midwest, whose numbers have been stagnating since a high in the first part of the 20th century.

Booming economies in states like Texas, Nevada, Arizona and North Carolina have drawn Americans away from struggling small communities in high-cost, cold weather states. In New York, 48 of 62 counties are estimated to be losing population. In Illinois, a state that also lost a congressional seat, 93 of 102 counties are believed to be shrinking. In 1970, the West and South comprised just under half the U.S. population — today it’s 62%.

That is shifting political power. In all, six states gained congressional seats: Colorado, Florida, Montana, North Carolina, Oregon and Texas, which gained two. Seven lost a seat: California, Illinois, Michigan, New York, Ohio, Pennsylvania and West Virginia.

Some states were incredibly close: New York was just 89 people short of keeping its seat, an expert at the Census Bureau said. And there were other surprises: Arizona, which demographers expected to gain a seat, did not. And though New York lost a seat, its population grew by more than 4% despite earlier census estimates that predicted the state would stay mostly flat.

The new decennial census counted 331,449,281 Americans as of April 1, 2020, said Dr. Ron Jarmin, the acting director of the Census Bureau. The total was up by just 7.4% over the previous decade, only slightly more than in the 1930s, when the population grew by just 7.3%. In that period, the birthrate rose once the economy started to climb out of the Great Depression. But this time it has continued to decline, after dropping in the wake of the Great Recession in 2008.


The lower birthrate, combined with the decline in inflows of immigrants, and shifting age demographics — there are now more Americans 80 and older than 2 or younger — means the United States may be entering an era of substantially lower population growth, demographers said. This would put the United States in line with the countries of Europe and East Asia that face serious long-term challenges with rapidly aging populations.

“This is a big deal,” said Ronald Lee, a demographer who founded the Center on the Economics and Demography of Aging at the University of California at Berkeley, noting that the United States had long outpaced other developed countries in population. “If it stays lower like this, it means the end of American exceptionalism in this regard.”

The once-in-a-decade process of counting all Americans redistributes political power based on where in the country people have moved. States that lose seats are not necessarily losing population, but are growing more slowly than the nation as a whole.

That was the case for California. For most of the 20th century, the Golden State was consistently among the fastest growing in the nation. Birthrates were rising, immigrants were flowing in as was a steady stream of people from other states. But over the past 30 years, its growth has slowed, in large part because of an exodus of residents to states with lower costs and booming economies like Texas and Nevada. Then, over the past decade, a falling birthrate and sharp slowdown in immigration caused the state to slip behind the nation.

According to estimates released in 2020, California had 10% fewer births in the 2010s than in the 2000s and took in 44% fewer immigrants.Idaho was one of the fastest growers and much of its growth was fueled by transplants from California, previous data show.

When Rachel Abroms and her husband, a psychologist with the Department of Defense, began looking for houses to buy in Coronado, on a peninsula in the San Diego Bay, a few years ago, even a starter home of about 1,500 square feet cost around 1 million dollars. So when her husband was offered a position in Boise, Idaho, they decided to move. They eventually bought a house that was twice as big for half the price.


“It’s more space,” said Abroms of the house that they bought in 2019. As for Boise, “it’s small and it’s manageable, and it’s pleasant.”

Another defining feature of the decade was the fall in immigration. Flows of immigrants had been rising for years, since a modern low in the 1970s. But they mostly leveled off after the Great Recession in 2008, and went into decline during the coronavirus pandemic, said Jeffrey Passel, senior demographer at the Pew Research Center.

Passel said the drivers were a worsening economy in the United States and tougher enforcement on the border with Mexico, especially after 2010. Also important, he said, were Mexico’s improving economy and its own lower birthrate.

“The change in the Mexican flows is really what caused immigration to level off,” Passel said, noting that Mexico had been the biggest source of immigration to the United States for years. He has calculated that, throughout the decade, there were more unauthorized Mexican immigrants leaving the United States than arriving.

The tapering of immigration overall has added to population woes in some states. Over the past decade, three had outright population declines: West Virginia, Mississippi and Illinois.

Illinois came close to breaking even, but still lost. Compared to the century’s first decade, Illinois had 15% fewer births and lost nearly 40% more residents to other states. Between 1990 and 2010, the state’s foreign-born population doubled to 1.8 million, but there was little growth after that. The state lost a congressional seat in the previous decennial census as well.


Population loss in Illinois has been felt most acutely in rural counties, particularly in the southern part of the state. Towns that were once thriving from manufacturing and the coal industry have seen residents gradually move away in search of jobs, and remaining residents say the quality of life has suffered as restaurants and other businesses have closed.

The Chicago area has been mostly flat in population in recent years, through an exodus of Black families from the city and a decline in immigration has caused alarm. The Chicago Metropolitan Agency for Planning, a regional planning group, said in a recent report that Illinois residents leave most frequently for Indiana, Florida, Texas, California and Wisconsin.

The final driver of the country’s extraordinarily sluggish growth over the past decade is a stubbornly persistent decline in the birthrate that has surprised demographers and prompted a debate over whether the delay in childbearing is a permanent new fixture in the lives of American women.

Aging populations can mean higher burdens for elder care, and slower labor force growth, with broad implications for the economy and the social safety net. But population slowdowns can also mean an improved outlook for the climate, said Lee, who is also an economist. And fertility declines also reflect women’s rising roles as professionals and labor force participants.

It is far from clear, Lee said, where the birthrate decline that has taken hold in many rich countries, and now, it seems, in the United States, is leading.

“It’s uncharted waters,” he said. “The consequences of low fertility are still unfolding.”