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.
The Tenth Amendment speaks to the fact that the Founders of our nation, our Republic, intended that the Federal government be limited in scope and power. It reiterated the intent that the people, and through them their own individual state, possessed all powers not specifically delegated to the Federal government, the "United States". Please remember that the"United States" were so called because the states joined together to accomplish some limited goals that were more easily realized in concert than separately. There was never any wish to relegate complete control to a central government (except perhaps by a few misguided, elitist individuals such as Alexander Hamilton.)
The Federal government, as all governments do when let off the leash by a lazy, distracted and unsuspecting citizenry, seeks to grow its power, to control all that it can. Because of this fact, the weakly written Commerce Clause has been interpreted by politicians and Presidents to mean that anything they wish can be controlled by the Federal government.
It was bad enough when the Federal government applied it to all items which physically moved between states, but since before WWII it has been applied to anything you do. Farmers who grew wheat and raised livestock and grew personal gardens all for their own personal use were harassed, arrested and convicted under the Commerce Clause. IIRC, the justification was that they were depriving the economy of other food producers in other states by not purchasing their produce, instead consuming their own. This continues to this day. The FDA and the Department of Agriculture can control what you grow and what you consume of and on your own property. Personal vegetable gardens, goats and cows kept for personal consumption of their milk and meat and offspring, wheat grown to make only your own bread or pasta.
Recently, several states - including the beautiful state of Montana where I currently am residing - have passed legislation, signed by their governor, which codifies that a firearm produced entirely within the state and kept only within that state is not subject to any Federal firearm laws. Montana was the first to pass such a law.
Of course, the Bureau of Alcohol, Tobacco, and Firearms (which many of us believe should be the name of a convenience store, not a Federal agency) is trying to convince people, and the legislature of the states involved, that Federal law supersedes state law. This may be true when considering laws that pertain to Federal powers granted by the Constitution, but as the Commerce Clause was not intended to control activities within a state that did not concern or affect other states' ability to conduct commerce with each other, it does not apply to the Firearms Freedom Act, which is entirely intrastate.
Here is a web site that speaks to this issue. Since this is a good "foot in the door" aimed at recovering some control from that which has been usurped by the Federal government, it should be supported by anyone who A) believes in "states rights", especially as written in the Constitution and reflected in the Tenth Amendment, and B) wishes to begin to curb the excesses of governmental control over ever aspect of our lives.
Please check out this web site, read conservative opinions written about the Commerce Clause and about the Tenth Amendment/states' rights. I say "conservative" because we all have heard the government's liberal, indeed socialistic interpretation of these issues: that you have no rights beyond those which the Federal government wants you to have, and only when it wants you to have them. In order to read anything other than that, you will have to force yourself to check conservative web sites which talk about the Bill of Rights, the Tenth Amendment, and the Fourth Amendment, which the Supreme Court is busy trashing through their social activism.