WASHINGTON » The wave of immigrants entering the United States slowed dramatically last year as the economy faltered and the government stepped up enforcement of immigration laws.

The nation added about a half-million immigrants in 2007, down from more than 1.8 million the year before, according to estimates being released today by the Census Bureau.

“;The U.S. is still a beacon for many people who want to come here for all kinds of reasons,”; said William Frey, a demographer at the Brookings Institution who analyzed the numbers. “;But what this shows is that the economy plays a big part in it.”;

The United States has added an average of about a million immigrants a year since 1990, including those in the country legally and illegally.

At more than 38 million, the number of immigrants in the United States is now at an all-time high. Immigrants made up 12.6 percent of the population in 2007, the largest share since 1920, when the nation was nearing the end of its last immigration boom, one that brought millions of people from Europe to the United States.

In Hawaii, the estimated number of immigrants, or foreign born, in the state last year was 221,448. That was a 5.4 percent increase from 2006, when the number was 210,162.

The immigration figures released today were from the 2007 American Community Survey, the government's annual survey of about 3 million households. The survey, which is replacing the long form from the 10-year census, yields reams of demographic, social and economic data about the nation.

Because the estimates come from a survey, each includes a margin of sampling error that makes year-to-year comparisons inexact. Annual immigration changes for many states and cities were within the margins of error, but the national trend was statistically significant: The nation's immigration boom slowed substantially in 2007.

Fourteen states showed declines in the estimated number of immigrants from 2006 to 2007, including New Jersey, New Mexico and South Dakota.

“;Immigrants have always come to the United States for jobs, but before they went to big immigration magnets to be with family or other immigrants,”; Frey said. “;Now the geography of where these people move is much more tied to the economy than ever before.”;

Much of the nation experienced a housing boom in the first half of the decade, providing jobs that attracted immigrants. The housing bubble burst last year, sending housing markets tumbling and contributing to a slumping economy that some economists believe is in recession.

The Census Bureau's estimates for immigrants include those in the country legally and illegally because it does not ask about legal status. Government and private estimates put the number of illegal immigrants in the United States at about 12 million.

A little more than half of U.S. immigrants are from Latin America and about a quarter are from Asia. About 13 percent are from Europe and 4 percent from Africa.

About one in five U.S. residents spoke a language other than English at home in 2007, about the same share as a year before.