Since the early 1780s, Madison, Hamilton, Washington, Robert Morris and others urged strengthening of the Articles of Confederation, which were dangerously deficient in their taxation, treaty, and commerce powers. They were known as strong "federal" men, and were called federalists. Unfortunately, the states could not agree on amending the Articles in these areas.
The name stuck to those who sought to strengthen the government while keeping it federal.
More on the topic: Whatever Happened to the Articles of Confederation Part V.
http://articlevblog.com/2017/01/whatever-happened-to-the-articles-of-confederation-part-v/