1790s
Best: “The Sleep of Reason Produces Monsters”
Runner-up: “Liberté, égalité, fraternité”
1800s
Best: “Tell it to the Marines”
Runner-up: “England expects that every man will do his duty”
1810s
Best: Dipsomania
Runner-up: Balkanization
Completely forgotten: “By God, sir, I’ve lost my leg!”
1820s
Best: “What a Pushkin, what a son of a bitch!’
Runner-up: Worldbuilding; pea soup fog
1830s
Best: Turtles all the way down
Runner-up: Almighty dollar; as the crow flies; lumberjack; shiver my timbers
1840s
Best: Lisztomania
Runner-up: Lumpenproletariat
1850s
Best: Chercez la femme
Runner-up: Muscular Christianity, Sea Peoples
1860s
Best: Heterosexuality
Runner-up: See a man about a dog
Older than I would have guessed: End of history, girlfriend, Great American Novel
1870s
Best: Highbrow
Runner-up: Jam tomorrow
1880s
Best: The quick brown fox jumps over the lazy dog
Runner-up: “You press the button, we do the rest”
1890s
Best: Hobo; monorail, “the love that dare not speak its name”
Runner-up: Brunch; curate’s egg; slice of life
Older than I would have guessed: What would Jesus do?
Completely forgotten: Will it play in Peoria?
1900s
Best: 23 Skidoo
Runner-up: “After you, Alphonse. No, you first, my dear Gaston”
Most Inscrutable: Rinehart
Older than I would have guessed: Simp
We must bring this one back: Oh! You Kid
1910s
Best: Faggot
Runner-up: “When life gives you lemons, make lemonade”
1920s
Best: Scofflaw
Runner-up: I say it’s spinach
We must bring this one back: Dumb Dora
1930s
Best: “Take my wife…please!”
Runner-up: “I’ll gladly pay you Tuesday for a hamburger today”; Boop-Oop-a-Doop; “The butler did it”; capsule wardrobe, “I will moida da bum”
1940s
Best: “Ain’t I a stinker?”/”What’s up, Doc?”
Runner-up: “You have two cows”
1950s
Best: “Let’s all go to the lobby”
Runner-up: Tyranny of numbers
Older than I would have guessed: “Don’t have a cow, man”; fakelore; frenemy; nothingburger
I may be one of the few who never forgot "Will it play in Peoria?" because I have an obsession with old timey language, theater jargon, and the questions of adapting a work for multiple audiences.
And we MUST bring back "Oh! You Kid!"
Oh gosh. Now I feel an urgent need to know some of the whys and wherefores behind several of these. I wonder if it's too much to hope that, having done the research to find them, you also have insight into their origin or use that would make for future offerings?