Philadelphia Convention Aftermath
In 1787, after the Philadelphia Constitutional Convention, the Federalists and Anti-Federalists locked horns over the ratification of the US Constitution, which was to replace the Articles of Confederation, thus starting off a debate which refuses to die down.

The basic difference between the Federalists and Anti-Federalists revolves around the definition of the two concepts. While 'federalism' refers to a system in which the administrative power is shared between the national and state governments, 'anti-federalism' is a system which believes that states should be more powerful than the national government. The Anti-Federalists are of the belief that the national government can either be as powerful as, or less powerful than, the state government, but cannot be superior to the latter.

Federalists Versus Anti-Federalists

With reference to the US politics, the Federalists are the people who support the present relationship between the federal government and governments of the fifty states, which came into effect with the ratification of the US Constitution in 1787. In contrast, the Anti-Federalists are those who oppose the current political structure. The tussle between these two groups can be traced back to the 18th century, when the committee which met to revise the Articles of Confederation concluded that its revision was not feasible and the entire constitution had to be rewritten.

The move was opposed by Anti-Federalist leaders who opined that the Articles of Confederation was apt for the future of the United States, and that the new Constitution defied the very concept of democracy. When these groups were pitted against each other over the ratification of the Constitution, one of the main issues was the inclusion of Bill of Rights, which the Anti-Federalists thought was necessary. It was this support for the Bill of Rights that gave them the much-needed momentum in their campaign. Anti-federalist leaders also argued that the newly drafted Constitution was against the democratic goals of the American Revolution.

In the end, the Federalists did manage to get all the thirteen states to ratify the Constitution, with the last state, Rhode Island coming on board on May 29, 1790. It's worth mentioning that the Federalist Papers, which were written by Alexander Hamilton, James Madison, and John Jay, played a crucial role in convincing the states to ratify the new Constitution. The adoption of the new constitution―the end of the American Civil War as some sources put it―marked the beginning of the power shift from the state governments to the national government, and the emergence of federalism in the United States.

Key Differences

In essence, a federalist is an ardent advocate of federalism―a political system in which sovereignty is divided between a central governing authority (the federal government) and constituent political units (the fifty states). On the other hand, an anti-federalist is an opponent of this concept. Instead, he believes that the state government should be the supreme authority. The difference of opinion is not just restricted to power sharing, but goes well beyond that.

Political Orientation
The Federalists were of the belief that the Federal government should be the supreme authority of the land, with powers to keep the states in control.
The Anti-Federalists were of the opinion that state governments should be the supreme authority, with the national government simply acting as a link between states.
The Federalists mostly comprised businessmen who took part in the American Revolutionary War.

Noteworthy Federalist Leaders: George Washington, James Madison, Alexander Hamilton, John Adams, and Benjamin Franklin.
The Anti-Federalists mostly comprised labor class from the rural areas of the country.

Noteworthy Anti-Federalists Leaders: Patrick Henry, George Mason, Samuel Adams, Robert Yates, and Richard Henry Lee.
US Constitution
The Federalists were in favor of the new United States Constitution which was adopted on September 17, 1787.
The Anti-Federalists were strongly against the Constitution; their argument, it gave more power to the national government.
Articles of Confederation
The Federalists opposed the Articles of Confederation, as they thought it reduced the national government to a toothless organization which was at the mercy of the states.
The Anti-Federalists believed that it was possible to retain the Articles of Confederation by amending it, instead of replacing it with an entirely new Constitution.
Bill of Rights
The Federalists argued that the Constitution and state governments were enough to protect individual freedoms of the citizens of the country, and therefore, there was no need of the Bill of Rights.
The Anti-Federalists argued that the Bill of Rights was necessary, as they believed that lack of the same would give the Constitution the power to overwrite the rights of citizens followed by the states.
Separation of Powers
According to the Federalists, the distribution of power in three independent branches ensured efficient administration with due respect to people's rights.
According to the Anti-Federalists, the different branches of administration, especially the executive branch, was given too much power.
The anti-federalist belief that the state governments should have more power than the national government was something that the Articles of Confederation also spoke of, which is why the Anti-Federalists supported the Articles as against the new Constitution. As opposed to this, federalist beliefs highlight the need of having a national government which is more powerful than the state governments to ensure that the states are kept in control.

Nevertheless, we can't ignore the fact that we got the US Constitution―the supreme law of the land today―in its present form only because of this tussle between the Federalists and Anti-Federalists. Absence of either group would have had made a huge difference. Even today, there are people who go by the belief that it would have been better if the Articles of Confederation was altered in a manner which would suit the confederation. At the same time, there is no dearth of people who believe that America is indebted to the new Constitution for the position it holds in the world today.