In a major victory for gun rights advocates, a federal appeals court on Tuesday struck down a ban on carrying concealed weapons in Illinois — the only remaining state where carrying concealed weapons is entirely illegal — and gave lawmakers 180 days to write a law that legalizes it.

In overturning a lower court decision, the 7th U.S. Circuit Court of Appeals said the ban was unconstitutional and suggested a law legalizing concealed carry is long overdue in a state where gun advocates had vowed to challenge the ban on every front.

"There is no suggestion that some unique characteristic of criminal activity in Illinois justifies the state's taking a different approach from the other 49 states," Judge Richard Posner, who wrote the court's majority opinion. "If the Illinois approach were demonstrably superior, one would expect at least one or two other states to have emulated it."

Gun rights advocates were thrilled by the decision. They have long argued that the prohibition violates the U.S. Constitution's Second Amendment and what they see as Americans' right to carry guns for self-defense.