The Alien and Sedition Acts were a series of four acts created by the Federalist party in the late 18th century. These laws were supposed to protect American citizens, but they only served to silence their Democratic-Republican opponents. These four laws were:
The Naturalization Act lengthened the residency requirement for citizenship from five years to fourteen years. This law was put in place because of the influx of European immigrants, who favored the Democratic-Republican party.
The Alien Enemies Act allowed the President to expel all aliens from the United States in time of war. As war had not been declared with France, this act was never used.
The Alien Act allowed the President to deport or imprison all aliens whom he considered dangerous to the country. This made many immigrants flee for fear of abuse of this power.
The Sedition Act prohibited anti-government activity. This made it illegal to speak or publish any criticism of government officials and the (Federalist-controlled) government itself. Many Democratic-Republican printers were indicted and even imprisoned for disobeying this law. To prevent this law being used against them, an expiration date of 1801 was placed upon it.
Even though the Federalists tried so hard to suppress the Democrat-Republicans, they ultimately failed. Seeing this abuse of power, many Federalists changed their party and voted for the Democrat-Republicans instead.