it is so superstitious it is not even funny people have no clue what they think they know
the answer is 10 years
No the federal government controls the trade between the states.
To prevent European expansion in the Americas
No the federal government controls the trade between the states.
The constitution should prohibit the states from participating in the international slave trade.
to regulate intrastate trade, as allow by the constitution
This is exactly what happened when the original colonies were governed by the Federalist Papers, which led to the Continental Congress and the founding of the Constitution for the nation. Each state would not take the other states money and trade between the states broke down. To alleviate the problem the states came together to work out the problems under the auspice of the Convention of States. What they ended up getting was the Constitution that radically changed trade, economic trade and international trade.
The United States Constitution protected the slave trade for twenty years. This protection was not to expire prior to the year 1808. After January first of that year, laws could take effect to end the slave trade in the United States.
By giving Congress the power to regulate trade within the states
The Constitution vested Congress with the authority to regulate trade with other nations, between the states, and with Native American Tribes in the Interstate Commerce Clause (Article I, Section 8, Clause 3).
By giving Congress the power to regulate trade within the states
Before the constitution, the United States government was based on the Articles of Confederation. However, these weren't successful because they gave too much power to the states and not enough to the central government. For example, the central government couldn't tax the states, they could only ask for money. The states didn't have to give them any. Also, the central government couldn't control trade between the states or the states and other countries. This meant that the states could charge ridiculous prices for goods and other countries wouldn't want to trade with the US.