Citing threats to the Union, President Abraham Lincoln suspends the writ of habeas corpus for all states. Article I, Section 9 of the Constitution permits such a suspension only “when in cases of rebellion or invasion the public safety may require it.” (Habeas corpus is Latin for “You have the body,” and the writ is used to challenge the legality of a prisoner’s detention.) Although the U.S. Supreme Court later will rule that only Congress has the power to suspend the writ, Lincoln ignores the high court.