The slave Dred Scott claimed that his residence in a free state transformed him into a free man. His lawsuit took many twists and turns before making its way to the Supreme Court in 1856. But when the Court ruled against him, the ruling sent shock waves through the nation and helped lead to civil war. Writing for the 7-to-2 majority, Chief Justice Roger Taney asserted that blacks were not and never could be citizens. Taney also ruled that the Missouri...