Border apprehensions are rising quickly and the demographic profile of apprehended migrants is changing.
While Mexico is the United States' largest source of immigrants, the number of Mexican immigrants living in the U.S. illegally has declined since 2007.
The number of migrant apprehensions at the U.S.-Mexico border rose by 42% in October and November of 2016 compared with the same two-month period in 2015.
This change comes after a period in which net migration of Mexicans to the U.S. had fallen to lows not seen since the 1940s.
From 1965 to 2015, more than 16 million Mexicans migrated to the U.S. in one of the largest mass migrations in modern history. But Mexican migration to the U.S. has slowed in recent years. Today, Mexico also increasingly serves as a land bridge for Central American immigrants traveling to the U.S.