Language Ananchronisms

The Continental Congress started printing dollars in 1775.
Before that there were Spanish milled dollars that had been around for more than a century and frequently used in the colonies, being brought in because of the trade with the Spanish islands of the Caribbean.
The dollar printed by the Continental Congress was based on and assigned a value equivalent to the Spanish dollar.

An English teacher told me that sort of thing happened on Little House on the Prairie all the time. I tended to notice other mistakes, such as that baseball had been invented when they showed a game being played, but baseball gloves had not and they were using them. Referring to a girls' basketball team before boys' basketball was even invented. I barely had to get out of my chair to reach for the World Book to confirm these mistakes, but apparently they couldn't afford a set of the World Book. On an episode I saw the other day, "Entrance of the Gladiators" op. 68 or "Entry of the Gladiators" (Czech: Vjezd gladiátorů), a military march composed in 1897 by the Czech composer Julius Fučík, was played when a circus came to town. Laura was born in 1867 so should have been about thirty when this music was written. In this episode she was in her early teens if that.

I wonder if Ben Franklin would have used that phrase had he ever heard it.

That's interesting. I always laugh because they tend not to use contractions in biblical/ancient Roman/Greek films. I think it's likely that speakers of the various Mediterranean and Middle Eastern languages of those periods used contractions. Of course, in the movies the actors are speaking modern English, but not using contractions makes them sound stilted.