“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.”
What does it mean, why did they think it was so important? And would we even have a constitution today if it weren’t for the 10th? All this and more.
https://blog.tenthamendmentcenter.com/2020/04/the-10th-amendment-an-introduction/