When the newly independent and sovereign states of the union formed, they had some hyperinflation problems so they told their representatives to go meet up and edit the Articles of Confederation to fix the problem.
We ended up scrapping the Articles of Confederation without significantly addressing the currency problems and just began from scratch...and from that came the Constitution. There were two important men present commanding two main groups at the drafting of the Constitution:
Alexander Hamilton and his buddies who were nationalists; favoring a strong central government and even a monarchy.
Patrick Henry and his buddies who were federalists; favoring strong states' rights.
Now, Mr. Hamilton was very sneaky. He named his group "the federalists" even though they were nationalists. He did this because the country had just had a revolution to get rid of a strong central government: King George III. He knew the people wanted to be part of sovereign states.
Mr. Henry named his group "the anti-federalists" because he of course was against Hamilton's nationalist ideas, but he had already taken the name of federalists.
The two groups wrote a series of letters and essays to convince the general population to vote in order to approve or reject the new Constitution.
These are known as the Federalists Papers (which are widely cited in court cases) and the Anti-Federalist Papers (which are basically ignored especially today.) If you have a child, look through their history book and search for the Anti-Federalist Papers. They're non-existent. Now look for the Federalist Papers.
Long story short: The population voted for the ideas of "The Federalists" (nationals), when what we fought a war
to have was the ideas of "The Anti-Federalists" (federalists).