According to the U.S. Constitution, which amendment reserves powers not specifically given to the federal government to the states?

The Tenth Amendment to the U.S. Constitution is pivotal because it explicitly outlines the principles of federalism by reserving powers not delegated to the federal government by the Constitution, nor prohibited by it to the States, directly to the states or the people. This amendment is crucial in establishing the balance of power between the national and state governments, ensuring that any authority not explicitly assigned to the federal government reverts to the states, thereby promoting state sovereignty.

The other amendments mentioned, while significant, do not address the distribution of powers between state and federal governance. The Eighth Amendment focuses on protections against excessive bail, cruel and unusual punishment, and the Sixth Amendment deals with rights related to criminal prosecutions, such as the right to a fair trial. The Fourteenth Amendment primarily addresses citizenship rights and equal protection under the law following the Civil War, and while it influences state legislation, it does not serve the purpose of reserving powers to the states in the same context as the Tenth Amendment.