US President Donald Trump recently invoked the Alien Enemies Act of 1798, leading to the deportation of immigrants. This law has only been used three times in U.S. history—during the War of 1812 and both World Wars.

The Trump administration has sent hundreds of Venezuelans accused of being gang members to a prison in El Salvador -- the first of whom arrived Sunday, pushing the limits of U.S. immigration law by carrying out the deportations seemingly after a federal judge ordered that the flights not proceed.