In “Arsenic and Old Lace”, Cary Grant and his bride to be are at the courthouse picking up their marriage lisence and a white man and his Asian bride are in the line ahead of them.
Also in “Showboat” there was in interracial couple–I don’t want to give a spoiler who it was though, but it was important to the story
I’d forgotten about that scene in
Arsenic and Old Lace. Capra probably didn’t care and was powerful enough that it probably didn’t matter. My mom probably saw it when it was released - and in the South - and growing up as an old movie buff I can’t remember her pointing it out as unusual. It was made during WWII, so I don’t know if that made a difference or not - and she lived in Norfolk, VA, HQ Atlantic Fleet, so lots of Navy around.
As for
Showboat…regarding the situation you referenced (and I’ll stick with your ‘no spoilers’ rule), consider what actually happened. Apply that with a 1920s filter (which is when the original play was written) and you might be surprised at who the bad guys
weren’t. Interestingly enough, one of the characters was the only character in the movie that nothing worked out for in the end…which would’ve fit with the era.
I think in the South more horror would’ve ensued if it had been a black and white couple over the above two, and that couple had been presented as husband and wife/couple of any sort in a serious manner (
Showboat being a musical may have mitigated the circumstances). That was a massive no no, and was what got
Guess Who’s Coming To Dinner? banned even after the laws had changed.
Edited to add: And don’t forget, the actress who played the role was always white.