Like many people, I think you have it backwards. This country was formed of states . . . individual states that made their own laws for their own residents.
But right at the first, it was realized that the states needed a sort of over-all entity that would raise an army to protect all the states, an arbiter to deal with trade and commerce between and among the states. This over-all entity was called the Federal Government, and the states gave the Federal Government only narrow responsibilities.
Now, we citizens have allowed the Federal Government to take enormous powers that are supposed to belong to the states. For example, the dept of Education is no way a power given the Federal government . . each state is meant to make education decisions based upon the ways of life of their own citizens.
Right now, the Federal Government says it can do anything it wants to, and neither we nor the state governments can do a darn thing about it. Thank-you to the Tea Party movement for understanding this, and demanding that the Federal Government back off.
establish its own constitution
In Australia each state and territory has its own set of Constitutional Laws that are legally binding to the original Constitution. Laws can be changed according to the constitution if the High Court can deem the State or Territory law unconstitutional.
Each states needs there own constitution for a few reasons. It is to tell them apart and make them what they are.
Each state in the US has it's own constitution, and it's own supreme court.
Yes, each state has its own individual constitution, but they all comply with the United States constitution.
Yes and Yes. The US Constitution applies to all the states. Each state has its own constitution that applies to that state. The state cannot contradict anything in the US Constitution, but they can add things that they feel are missing, or have more stringent requirements for certain things. And the state's constitution sets up and defines the government that will rule the state.
Could impose its own tariffs
Each state held its own ratifying convention
This would depend entirely on which state is involved. For some states, the legislature and governor can amend the constitution, or the people can amend it with an initiative. Each state has its own process.
Every state has its own constitution.
According to the Constitution the President of the United States is elected based on the votes cast from each state. Each political party chooses their own candidate to represent them.
Federalism contributed to economic and political differences among the states because it allowed each state freedom to make its own laws. Each state was also able to draft its own constitution.