slaves be counted as three-fifths of a person in the U.S. Census for the apportionment of members to the U.S. House of Representatives. Reached as a compromise between the Northern free states and the Southern slave states. Article I, Section 9, Clause 1: Prohibited Congress from prohibiting the international slave trade before the year 1808. Article IV, Section 2, Clause 3: Mandated that runaway slaves must be extradited to their state of origin. Ratified Amendments Thirteenth Amendment (1865) - abolished Slavery in the United States. Fourteenth Amendment (1868) - extended U.S. citizenship to all natural-born residents, including African-Americans; guaranteed due process to all U.S. citizens; and temporarily barred former supporters of the Confederacy from holding public office. Fifteenth Amendment (1870) - guaranteed voting rights to all male U.S. citizens, including African-Americans. Nineteenth Amendment (1920) - guaranteed women's suffrage, including to African-American women. Twenty-fourth Amendment (1964) - abolished the poll tax in federal elections. Unratified or Proposed Amendments Crittenden Compromise (1861) - Proposal to avert the American Civil War by amending the U.S. Constitution to explicitly legalize slavery in the American South and prohibit its abolition. Rejected by Congress and President Abraham Lincoln. Corwin Amendment (1861) - proposed to prohibit the federal government and future constitutional amendments from interfering with the "domestic institutions" of individual states, implicitly including slavery. Endorsed and signed by President James Buchanan but not ratified before the Civil War Federal court decisions Decisions North Carolina v. Mann (1830) - Ruled that slaveholders had absolute authority over slaves, including to commit acts of violence against them. Prigg v. Pennsylvania (1842) - Overturned Pennsylvania state law prohibiting free blacks from being forcibly taken to the South and enslaved. Dred Scott v. Sandford (1857) - Effectively overturned the Missouri Compromise prohibiting slavery in the North and ruled that African-Americans were not U.S. citizens. Slaughterhouse Cases (1873) - Limited enforcement of the Privileges and Immunities Clause. United States v. Cruikshank (1876) - Ruled that the Bill of Rights did not apply to state governments. United States v. Reese (1876) - Narrowed interpretation of the Fifteenth Amendment. Strauder v. West Virginia (1880) - Limited enforcement of the Civil Rights Act of 1866. Plessy v. Ferguson (1896) - Ruled racial segregation and Jim Crow laws in the South to be constitutional under the "separate-but-equal" doctrine. Williams v. Mississippi (1898) - Upheld voting restrictions in the 1890 Mississippi State Constitution. Cumming v. Richmond County