Answer: Allowed the president to deport noncitizens considered dangerous.
Explanation:
The Alien Enemies Act was part of the Alien and Sedition Acts which were passed through Congress by the Federalist party under President John Adams during a time when they feared going to war with France. These acts were meant to prevent support of the French amongst immigrants who habored French sentiments.
The Alien Enemies Act gave the President the power to arrest and then deport noncitizens of the US or rather citizens of other countries that the US were at war with as they were considered dangerous.