A new analysis of monthly Census Bureau data by the Center for Immigration Studies shows that the nation's immigrant population (legal and illegal) hit a record high of 42.1 million in the second quarter of 2015 — an increase of 1.7 million since the same quarter of 2014

Growth in the immigrant population in the last year was led by a 740,000 increase in the number of Mexican immigrants. The nation's immigrant (foreign-born) population, which includes legal and illegal immigrants, grew by 4.1 million from the second quarter of 2011 to the second quarter of 2015. Immigrants are 13.3% of the nation's total population — the largest share in 105 years. Growth in the last year was led by a rebound in the number of Mexican immigrants, which increased by 740,000 from 2014 to 2015 — accounting for 44% of the increase in the total immigrant population in the last year. The total Mexican immigrant population (legal and illegal) reached 12.1 million in the second quarter of 2015 — the highest quarterly total ever. In addition to Mexico, growth in the immigrant population was led by a 449,000 increase in the last year from countries in Latin America other than Mexico. The Department of Homeland Security and other researchers have estimated that eight in 10 illegal immigrants are from Mexico and Latin America, so the increase in immigrants from these countries is an indication that illegal immigration has begun growing again.