President Trump's executive order challenging birthright citizenship will face its first legal test in a Seattle courtroom Thursday.

A federal judge is set to hear the first arguments in a multi-state lawsuit seeking to block President Trump’s executive order ending the constitutional guarantee of birthright citizenship regardless of the parents' immigration status.

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.