More than 30 countries grant unrestricted birthright citizenship based on the ‘jus soli’ principle – and nearly all of them are in the Western Hemisphere. The reason is more complicated than you might think.

One of the many executive orders President Donald Trump signed on Monday included one to end birthright citizenship. Here's what to know about it and why lawsuits have already been filed.

A federal judge Thursday blocked President Donald Trump’s executive order outlawing birthright citizenship —the policy automatically giving citizenship to anyone born in the U.S.—and declared it “blatantly unconstitutional,” as legal experts widely believe the president does not have the power to change the policy on his own.