Factual error: When in Harrisburg Suzy mentions the civil war museum, but that didn't open until 2001.
Continuity mistake: When Midge is doing her make up routine she doesn't have eye liner then she does then she doesn't.
Continuity mistake: When Joel is about to start his show a woman in front holds a cigarette with her right hand. In the immediate next angle she's holding it with her left hand.
Sacha
Factual error: Taxicabs appearing in various scenes show that they are fitted with side marker lights on the fenders. Those were not used on American cars until 1968.
Other mistake: When Midge is doing her skit for the soldiers she is pretending to read articles off a magazine. Yet instead of flipping the magazine, she is swiping as if reading off a smartphone.
Factual error: Midge talks about a 2 for 1 pantyhose sale but pantyhose weren't introduced until 1959.
Factual error: The word "floaties "was not used to refer to pool toys in the 1950's.
The Disappointment of the Dionne Quintuplets - S1-E4
Factual error: When Midge is moving to her parents' apartment there is a stack of books on the table while her son is watching TV. On top is a Nancy Drew book (the back of the book which is yellow). However publisher didn't introduce the editions with the yellow back covers until the 1960s.
Factual error: In the Greenwich Village record shop, the vinyl records are shown with polythene sleeves. At that time, vinyl LP's were always factory sealed in cellophane shrink (unless it was later removed), not poly sleeves.
superfishContinuity mistake: When Midge and Susie go see Michael Kessler, one of the mugs on his desk keeps moving between shots throughout the scene.
THGhostThe Disappointment of the Dionne Quintuplets - S1-E4
Continuity mistake: After Midge puts down Joel's ornamental duck down for the final time before she leaves his new apartment, the position of the duck changes in the following shot.
THGhostContinuity mistake: While Midge's dad is questioning her about her new job, Midge starts buttering her toast with some jam. But in the following shot there is no jam on her toast.
THGhostMrs. X at the Gaslight - S1-E6
Continuity mistake: The cookie that Midge trades Noah for a cigarette for keeps moving between shots.
THGhostFactual error: Abe hilariously exercises in a ridiculous suit while listening to Robert Preston's "Chicken Fat" recording. But Preston (who starred in The Music Man) didn't release this until 1962, at the behest of President Kennedy, who was big on physical fitness.
