The U.S. Supreme Court's ruling in the Dred Scott case struck down the Missouri Compromise as unconstitutional, maintaining that Congress had no power to forbid or abolish slavery in the territories.
the court decided that all people of African ancestry -- slaves as well as those who were free -- could never become citizens of the United States and therefore could not sue in federal court. The court also ruled that the federal government did not have the power to prohibit slavery in its territories. Scott, needless to say, remained a slave.