Add Yahoo as a preferred source to see more of our stories on Google. Immigrants to the U.S. increasingly arrive like these people, seeking asylum at a formal border crossing, rather than trying to ...

Immigrants to the U.S. increasingly arrive like these people, seeking asylum at a formal border crossing, rather than trying to sneak across the border. Carlos Moreno/NurPhoto via Getty Images ...

Undocumented immigration is a key issue in American politics, but it can be hard to nail down the basic facts about who these immigrants are, where they live and how their numbers have changed in the ...