The 14th Amendment was passed in July 1868, after the American Civil War. It provided US citizenship to people who had been enslaved within the country. Thirty years later, the Supreme Court ruled that people born in the United States were automatically citizens under the 14th amendment. In October 2018, President Donald Trump called for an end to birthright citizenship. He said he would eliminate it with an executive order. But experts said that would violate the Constitution.