What is the origin of smart Alec?

The term 'smart Alec' came from the exploits of Alec Hoag, a celebrated con man in New York in the 1840s. He and his wife Melinda and an accomplice known as French Jack, operated a con called the Panel Game, a method by which prostitutes and their pimps robbed customers.

The game consisted of sliding walls that would enable Hoag to sneak in while the victim was sleeping and steal valuables. Because he never woke the victim, 'Smart' Alec Hoag would make good his escape before the victim even knew what had happened.