Mexico. That's probably the first country
that pops into your head when you hear
about immigrants who are in the U.S.
illegally. And yes, Mexicans do make up
the largest group of unauthorized
immigrants, but their numbers have been
dropping since the Great Recession. For
the first time in more than a decade,
estimates indicate the majority of
unauthorized immigrants are no longer from Mexico.
Instead, we're seeing people
from Central America and Asia.
Most unauthorized immigrants have been 
in the U.S. for a decade or longer
and many have children who are U.S. citizens.
One thing we don't know, is the breakdown
of how people entered the U.S.
How many crossed the
border illegally? And how many entered
with valid visas and stayed in the U.S.,
never returning home?
The federal government can't say. For decades they
have not been tracking this data consistently.
But we do have numbers for
the past two fiscal years and the
country with the most visa overstays?
Canada.
