Anti-federalism was a disagreement with the idea of creating a strong central government in the United States. In the late 1700s, the leaders of the colonies got together and wrote the Constitution, which is a document that created the government. Some people, called anti-federalists, thought it was a bad idea to create a strong central government that could control all of the states. They were worried that it could be too powerful and might not protect the rights of the states and the people. So, they wanted a system where the states would be able to make their own laws and not be controlled by the federal government.