Final answer:
The Constitution reserves to the states all powers not delegated to the national government or prohibited to the states, as stated in the Tenth Amendment.
Step-by-step explanation:
The Constitution does ensure that states retain all powers not specifically granted to the national government. This principle is encapsulated in the Tenth Amendment, which is part of the Bill of Rights. The amendment states: "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people." Essentially, this creates a group of powers known as reserved powers that are exclusive to state governments.
While the Constitution delegated more power to the federal government than under the Articles of Confederation, it also acknowledged the important role of states. For instance, states have the sovereignty to establish local governments and account for their structure and functions. Moreover, they possess the power to ratify amendments to the U.S. Constitution, providing them with a voice in constitutional changes. All amendments to the Constitution have been proposed by Congress and then ratified by the states, with the exception of the Twenty-First Amendment, which used a state ratifying convention.