The Bill of Rights
McCulloch v. Maryland
In the McCulloch v. Maryland case a bank owner, McCulloch, wanted to expand a branch of his bank to Baltimore, Maryland. Maryland was angered by this and wanted to tax the bank for not getting approved by the federal government in Maryland, but the bank had already been approved in Pennsylvania. Thus making it a federal establishment, which the right is taken away, since the constitution says you cannot tax the federal government. There they use the 10th amendment to establish there bank.
There is a boy named Joe that lived in Oklahoma. Joe's dad wanted to open a gas station and sell lottery tickets. Since it is illegal to sell lottery tickets in Oklahoma, Joe's dad decided to open the gas station in Texas. This allows Joe's dad to sell lottery tickets in his gas station. Since the Constitution does not restrict the right to sell lottery tickets that right goes to the states. This gives the states the right to make their own laws on selling lottery tickets. They can determine whether or not to allow them to be sold and in addition determine age restriction. This is also an example of the 10th amendment of the Bill of Rights. The 10th amendment works to lay-out a catch all for matters not addressed by federal law. It re-enforces the concept that federal law and state law are divisible.