delegated powers are also called Enumerated Powers. It's a list in Article 1 Section 8 of the US constitution that give the Congress those specific powers.
Three examples:
(1)Borrow money on the credit of the United States
(2)Regulate commerce with foreign nations, among the several states and with the Indian Tribes\
First, it brought slavery to an end. Slavery ended with the ratification of the thirteenth amendment. Second, it showed Americans that fighting a civil war is not the way to go.