In 1798, with the U.S. preparing for what it believed would be a war with France, Congress passed a series of laws that increased the federal government’s reach. The Alien Enemies Act was created to give the president wide powers to imprison and deport noncitizens in time of war.

President Trump invoked the Alien Enemies Act of 1798 against Tren de Aragua members, provoking a legal fight. Here's what to know about the controversial law, which was last used during World War II.

The Alien Enemies Act of 1798 gives the president wartime powers to deport undocumented immigrants with little to no due process.