Article I, section 8, clause 4 of the Unite States Constitution expressly gives the United States Congress the power "(t)o establish a uniform rule of naturalization." The Immigration and Naturalization Act sets forth the legal requirements for the acquisition of, and divestiture from, citizenship of the United States. The requirements have become more explicit since the ratification of the Fourteenth Amendment to the Constitution, with the most recent changes to the statutory law having been made by the United States Congress in 2001.