Factual error: When in Harrisburg, Susie mentions the Civil War Museum, but that didn't open until 2001.
Suggested correction: She could be talking about another museum (either real or fictional) with the same name that existed in this time period and had since closed. It's a fairly generic name.
Factual error: The word "floaties "was not used to refer to pool toys in the 1950's.
Suggested correction: I was a kid in the 50s, and the term pool "floaties" or "floaters" was used. It wasn't commonly used.
Factual 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.
Suggested correction: It's true that this song was not recorded and released until 1962, which is a little after when this scene take place. However, Abe is not actually "listening" to it (or any other music) as he is exercising on the lake dock. The song is used as part of the series soundtrack and creates a desired effect and mood for the scene. As the storyline is now in the early 1960s, it is appropriate to the era, and is only background music.