In March 1857, the Supreme Court issued a 7–2 decision against Dred Scott. In an opinion written by Chief Justice Roger Taney, the Court ruled that black people "are not included, and were not intended to be included, under the word 'citizens' in the Constitution, and can therefore claim none of the rights and privileges which that instrument provides for and secures to citizens of the United States." Taney supported his ruling with an extended survey of American state and local laws from the time of the Constitution's drafting in 1787 that purported to show that a "perpetual and impassable barrier was intended to be erected between the white race and the one which they had reduced to slavery." Because the Court ruled that Scott was not an American citizen, he was also not a citizen of any state and, accordingly, could never establish the "diversity of citizenship" that Article III of the US Constitution requires for a US federal court to be able to exercise jurisdiction over a case. After ruling on those issues surrounding Scott, Taney continued further and struck down the entire Missouri Compromise as a limitation on slavery that exceeded the US Congress's constitutional powers.