How does the constitution determine which powers are to be held by the states?

In the 10th amendment of the US Constitution, it clearly states that any power not given specifically to the federal government or denied to the states, will belong to the state governments. These powers are known as reserved powers. This constitutional amendment allows states to make their own laws for a variety of different issues in their states including:

1) Driving laws- including speed limits, age in which individuals can obtain a license, etc.

2) Education- States have the power to adjust their graduation requirements, the courses they teach to students, and the curriculum used by teachers.

The Constitution determines which power are to be held by the states by including an amendment that says so, more specifically the 10th Amendment, which, in order to limit the government's scope and give power to the states, established that all power not delegated to the federal government by the Constitution, nor prohibited by it to the states, are reserved to the states respectively, or to the people.

For example, because the Constitution says nothing about granting the power to the government to make policy to regulate wages and working hours, each state has the power to make a policy regarding the issue, as long as it does not violate the Constitution.