The Supremacy Clause of the Constitution states that the Constitution and the laws passed by congress are the supreme law of the land. Another clause found in the Constitution is the Full Faith and Credit Clause which ensures judicial proceedings in one state are respected by other states. The Privileges and Immunities Clause and the Commerce Clause explain how Supreme Court rulings in various cases throughout the years have shaped relationships between the federal and state governments. Additionally, in the beginning, the Bill of Rights only applied to actions by the federal government, and the state governments were not obligated to uphold those rights. However, the Supreme Court interpreted the Fourteenth Amendment stating that it only concerned privileges and immunities that came with being a citizen of the United States, not the citizen of a state. Over the years, the court changed its way of thinking and adopted a policy known as the Incorporation Doctrine. The Court decides over time and on a case by case, which provisions of the Bill of Rights will extend to the states. Part of the Exploring Our Nation Series.