People celebrate as they become U.S. citizens during a naturalization ceremony at the National Archives Museum in Washington.
The United States accepts the largest number of legal immigrants in the world. Only about 4 percent are Muslim.
But in Europe Muslims make up about 40 percent of immigrants and it is more difficult for them to integrate into society, says Nancy Foner, a professor of sociology at City University of New York and co-author of "Strangers No More: Immigration and the Challenges of Integration in North America and Western Europe."
One reason? The US is much more tolerant of different religions than in Europe, which tends to be more secular.
"In the US, religion is more accepted," she says. "In Europe, religion — Islam in particular — is a major barrier for immigrants. And there's a big focus to the threat that Muslims will undermine core democratic values in Europe."
Her book compares the experience of low-income immigrants in Western Europe versus those in the United States.
Foner says despite the fact that more immigrants are actually working in the US, the poverty rate for US immigrants is higher than for immigrants in Europe. That's because immigrants in the US often work in low-paying jobs and both documented and undocumented immigrants in Europe are often entitled to the same rich array of public benefits, such as housing and healthcare, that are offered to European citizens.
But Foner says many immigrants in Europe feel less accepted than those who come to the US.
"The US see immigrants as Americans in the making. It's OK to hold on to your ethnic identity as long as these are additions to a fundamental American core. In European countries it is more difficult, " she says. "The immigrants and their children may feel French and feel German, but often the German and the French don't recognize them that way."
But she says immigrants in Europe are less segregated when it comes to housing than those who live in the US, especially immigrants from Africa and the Caribbean, who make up about 10 percent of US immigrants.
"Rates of residential segregation are actually higher in the US particularly among Black immigrants than we find in Europe," she says. Because of the US's history of slavery and long-term institutionalized racism, she says, "black immigrants are having an easier time integrating in many ways in Europe than in the US."