These days, smart alecs (or alecks, depending on who you ask) are people who are obnoxiously conceited and think they're pretty clever. At one point, it was thought that this term was simply generic and that Alec wasn’t actually a real person. But research done by Professor Gerald Cohen in 1985 for “Studies of Slang Part 1," as well as research by other historians, has shown—based on considerable newspaper article evidence—that “Alec” was probably a real person, namely Alec Hoag.
Partners in Crime
Hoag was a pimp and a thief in New York City in the 1840s. He would rob his wife Melinda's “customers” while she distracted them.
At first, the scheme worked like this: Melinda led a victim into a dark alley, where she picked his pockets. Then she embraced the victim and held her hand out behind him, where Hoag was hiding to grab the stolen goods.
Inevitably, some of these men would go to the police to report the thefts. To protect himself and his wife from arrest, Hoag enlisted a couple of police officers by promising to split the stolen goods with them. But Hoag's downfall came when he ran into some financial difficulties and couldn't give the officers their fair share.
Initially, he got away with this by operating a “panel game” con. Melinda would bring the men back to her apartment—and then, according to George Wilkes, editor of the Subterranean (who met Hoag in prison while Wilkes was falsely imprisoned), “Melinda would make her victim lay his clothes, as he took them off, upon a chair at the head of the bed near the secret panel, and then take him to her arms and closely draw the curtains of the bed. As soon as everything was right and the dupe not likely to heed outside noises, Melinda would give a cough, and the faithful Alec would slyly enter, rifle the pockets of every farthing or valuable thing, and finally disappear as mysteriously as he entered.”
Sometime after that, Alec would bang on the door, and Melinda would make out that he was her husband who had returned early from some trip. The victims then would hastily grab their clothes and escape through the window.
Cheaters Never Prosper
The police soon discovered Hoag was cheating them out of their share by this new tactic and arrested Hoag and Melinda. Hoag promptly escaped from prison, with the help of his brother, but was eventually recaptured.
Alec Hoag was then given the nickname “Smart Alec” by the police for being too smart for his own good. The thought is that the police then used this term when dealing with other criminals who seemed a little too smart for their own good, often thinking of ways around giving police their payoffs: “Don’t be a Smart Alec.”
This term, as an expression, then took about 20 years to germinate and eventually found its way into print in 1865, and popular culture shortly thereafter.