Each state has its own different interests, but if they want to become a union they have to work out some hierarchy between states and nation, as well as representation in the national government.
After the Articles of Confederation were instated, states were acting to much like separate nations with things like:
- Imposed tariffs on each other
- Each had their own militia instead of the nation having an army.
- Not giving the national government enough tax money.
To try to stabilize the Union every state, except Rhode Island, sent delegates to Philadelphia to alter the existing form of government and give the nation a second chance.