Federalists were individuals who were in favor of a stronger federal (aka central) government. Federalists believed that the US needed a stronger federal government after the Articles of Confederation, America's first constitution, were a failure. The Articles of Confederation gave almost no real power to the federal government. This resulted in several different problems.
This is why the federalists favored a stronger federal government that had the ability to tax, regulate trade between states, and negotiate deals with other nations.
