Matthew 12:39 But he answered and said unto them, An evil and adulterous generation seeketh after a sign; and there shall no sign be given to it, but the sign of the prophet Jonas.
The sign of the prophet Jonas refers to Jonah being 3 days and 3 nights in the belly of the whale and equates to the Lord Jesus Christ who was 3 days and 3 nights in Hell, and then arose. Jonah preached to the Ninevites and they repented, but fell away 120 years later and God destroyed them. They repented on less evidence than America has been given, therefore the Ninevites will condemn that generation which does not repent. No generation and no country has had the gospel presented so clearly for so many generations as has America. Never has America been this apostate.
Ps 9:17 The wicked shall be turned into hell, and all the nations that forget God.