I remember watching The Hurt Locker (starring Jeremy Renner), the movie is meant to depict the Iraq War in 2004 but for some reason there’s a scene where an iPod Touch (releases in 2007), XBOX 360 (releases in 2005) and Gears of War (releases in 2006) present in the barracks even though these did not exist yet. Another anachronism from this movie is when a American soldier spots an Iraqi recording him ready on uploading the footage via YouTube (the website didn’t exist yet until 2005 when the story is set in 2004).
This is one of the things that makes me fucking adore the Temeraire series: the protagonist has a father who is staunchly abolitionist and yet the protagonist himself doesn’t really think about it at all, until quite a bit later in the series when he starts realizing that slavery isn’t just some theoretical thing in “the colonies”.
Meanwhile the dragon protagonist goes “um, isn’t that absolutely horrifying? am i missing something here??” when he learns about the existence of slavery, and this is absolutely pivotal to a lot of the plot in the later books!