In the late 18th century, both during and after the Revolutionary War, America's founding fathers drafted three versions of the constitution.
The first version was called the Articles of Confederation and was drafted in 1777 during the Revolutionary War, which started in 1765. Under the Articles of Confederation, each state had its own sovereign government. While there was a federal government, it was made extremely weak, granting all primary power to the states. The federal government would only be responsible for defense and the protection of the general liberties and welfare of the citizens. However, the founding fathers soon realized that the Articles of Confederation left the central government too weak in that it did not grant Congress the ability to levy taxes, did not have any way to enforce laws made by Congress, and it didn't provide a national court system. Deciding they needed a stronger central government, the founding fathers next drafted the Constitution of the United States in 1787.
At the convention held in 1787, the founding fathers decided to devise a stronger central government consisting of three branches: the executive branch, the legislative branch, and the judicial branch. They also devised a system of checks and balances to ensure that each branch had a means of vetoing decisions made by the other branches, thereby ensuring that power was not concentrated in one branch.
In 1791, the founding fathers next kept the 1787 draft of the Constitution intact but also added The Bill of Rights, which is 10 amendments to the Constitution written to ensure that individual rights are protected, such as the right to free speech. The Tenth Amendment was written to address the question of how the individual states' governments should now function in the absence of the earlier Articles of Confederation. Under this amendment, any powers not specifically reserved for the Federal government nor forbidden by states are powers that the states can wield, such as decisions concerning divorce laws, voting methods, levying state taxes, and decisions concerning public schools and police department procedures.