If you asked people what was the worst decision in Supreme Court history, you would get all kinds of answers. Liberals, for example, might say something like District of Columbia v. Heller (a pro-gun-rights decision), and conservatives might say something like Roe v. Wade (a pro-abortion decision). But one thing conservatives and liberals can agree on is the notoriety of another decision - the one my own vote for the worst decision goes to. The case is an old one from 1857, four years before the Civil War broke out. This is a decision that upheld the constitutionality of slavery, and put the liberty of free blacks in the North in jeopardy, to a degree not seen in any previous decision.
Dred Scott, a fugitive slave the court refused to free
The case was Dred Scott v. Sanford, and I would vote it as the most infamous decision in Supreme Court history. The decision said that persons of African ancestry "had no rights which the white man was bound to respect" - that they were "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," that they had "no rights or privileges but such as those who held the power and the Government might choose to grant them." It argued that when the Declaration of Independence said that "all men are created equal," and "endowed by their Creator with certain unalienable rights [such as] life, liberty, and the pursuit of happiness," that "the enslaved African race were not intended to be included, and formed no part of the people who framed and adopted this declaration."
Chief Justice Taney, who wrote the Dred Scott decision
In defending this decision, the Supreme Court claimed that there were "two clauses in the Constitution which point directly and specifically to the [black] race as a separate class of persons, and show clearly that they were not regarded as a portion of the people or citizens of the Government then formed ... One of these clauses reserves to each of the thirteen States the right to import slaves until the year 1808 ... And by the other provision the States pledge themselves to each other to maintain the fight of property of the master, by delivering up to him any slave who may have escaped from his service, and be found within their respective territories ... And these two provisions show, conclusively, that neither the description of persons therein referred to, nor their descendants, were embraced in any of the other provisions of the Constitution; for certainly these two clauses were not intended to confer on them or their posterity the blessings of liberty, or any of the personal rights so carefully provided for the citizen." (close quote)
The Constitutional Convention
Dred Scott was bad constitutional law as well as bad morally; because even though the original Constitution protected slavery through the slave importation clause and fugitive slave clause mentioned in Dred Scott (and some other clauses not mentioned there), it did not say that every person of African descent was legally a slave - the concept of race was not dealt with in the Constitution until the Thirteenth Amendment, which prohibited slavery for all persons regardless of race - and even then, the concept of race was not mentioned explicitly. It just prohibits slavery for everyone, without directly stating the implied premise "regardless of race." Race was not mentioned explicitly until the Fifteenth Amendment, which said that "The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of race, color, or previous condition of servitude."
Dred Scott painting
Because the Constitution never said once that all blacks were slaves, its protections of slavery did not apply to the enslavement of all blacks - only the ones held in chains at that time and their descendants. There were such people at that time as free blacks, and there continued to be so up through the time of Dred Scott - and beyond. The fact that this had been permitted since the beginning invalidated Dred Scott's argument that blacks had all been considered slaves from the beginning. While they made a valid argument for blacks historically being considered different from whites under American law, they were unable to back up their claim that blacks were also historically considered slaves without exception. Thus, Dred Scott was bad constitutional law as well as bad morally, and had not even the justification of the law.
William Lloyd Garrison, abolitionist
Frederick Douglass, abolitionist and former slave
The thing that frightened abolitionists most about Dred Scott was not that it upheld the constitutionality of slavery - that was nothing new, and slavery had been written into the original Constitution with disturbing clarity. What frightened them most was that it had the potential to turn all free blacks into slaves - thus enslaving many persons who were considered free even then. Dred Scott was an infamous decision; but it eventually backfired on the deciding justices, by growing the abolitionist movement into a powerful political force. Abraham Lincoln did not promise to end slavery where it already existed - he actually promised the contrary, knowing he'd never be elected without doing so - but he did pledge to stop the spread of slavery into the frontier. This was more than was promised by many other candidates of the time, and as much abolition as the Northern public was willing to allow; and it would never have been allowed at all without the enraged Northern reaction to Dred Scott.
All things considered, Dred Scott was a terrible decision - it was the most infamous decision in Supreme Court history. But it backfired on the deciding justices by making possible the election of a candidate sufficiently antislavery to cause Southerners to start a civil war they would lose, and destroy slavery along with it through so doing. If Dred Scott was not the beginning of the end, it was awfully close - the very beginning was the Fugitive Slave Law of 1850, which likewise grew the abolitionist movement, allowing white people to be punished for helping fugitive slaves (something new at that time, and going beyond the Fugitive Slave Clause of the Constitution). But Dred Scott gave the abolitionist movement political power unlike anything that had ever been seen before. Dred Scott strengthened slavery in the short run, but destroyed it in the long run, by setting in motion the chain of events that led to total abolition.
Fugitive slaves working in Union army, circa 1862
African-American troops in the Union army, 1865
Slavery is now dead once and for all, and we owe the happy death of slavery to the enraged Northern reaction to Dred Scott, and the critical proslavery error in allowing it. It was a tactical error on their part, and one which led to the very abolition they had tried to prevent. Thus, it brought the end of slavery that had been so long prayed for, and heralded the new birth of freedom.
Slavery in the Constitution's "Three-Fifths" Compromise
Frederick Douglass: The forgotten antislavery leader
Civil War miniseries (PBS)