1. Alien ActEdit
The Alien Act allowed the President to expel any aliens from the country without due process of law. Generally considered a violation of the Due Process Clause of the US Constitution. The Alien Act had a sunset clause, (it automatically expired after 2 years) and was never challenged before the Supreme Court. This act became law in 1798, while all appointees of the Supreme Court were Federalists, and predates the doctrine of Judicial Review.
2. Sedition ActEdit
The Sedition Act outlawed speaking out against the federal government ("sedition"). This was done largely because the Democratic-Republican minority newspapers and tabloids were criticizing the Federalist Party and the Adams Administration. There was hotly debated foreign policy work going on at the time, and Alexander Hamilton's Federalist Party and President John Adams did not wish dissent.
Soon after the passage of this act, John Adams became aware that his cabinet was controlled by Hamilton rather than himself, took steps to eliminate Hamilton's people from the Administration, renegotiated a Treaty with France, disbanded the standing Army which Hamilton had been creating, and gave Alexander Hamilton his walking papers. Adams actions, and Hamilton's catty reaction to them, likely led to the downfall of the Federalist Party, but the US was saved from war with France and the grip of the would-be Caesar, Alexander Hamilton.
The Sedition Act prohibited press criticism of Federalist policies and Government, but did not prohibit criticism of Vice-President Thomas Jefferson or the competing Democratic-Republican Party. The Sedition Act had a Sunset Clause (It automatically expired at the end of John Adams' Presidency) and was never directly Adjudicated by the Supreme Court. In a 1964 case, the Supreme Court noted that this 1798 Act had been unconstitutional.
3. Naturalization Act Edit
The Naturalization Act of 1798 increased the requirement for aliens wishing to become US citizens. The notice period was increased from 3 to 5 years, and the residency requirement was increased from 5 to 14 years. The Naturalization Act is believed to have been an attempt to limit the growth of immigrant population which was an important part of Democratic-Republican support. The naturalization Act of 1798 was repealed in 1802 by the then Democratic-Republican dominated Legislature.
4. The Enemy Alien Act Edit
The Enemy Aliens Act of 1798 granted the President the power to apprehend, restrain, remove, and confiscate the property of enemy aliens. Of the four Alien and Sedition Acts, this is the only one which remains in effect though in modified form. The Enemy Alien Act was the legal basis for the actions (Interments and confiscations) against Japanese-Americans and to a lesser degree German-Americans during WWII.