The other day I watched a short subject from the 1940s on TCM that consisted largely of some sanitized history (with Craig Stevens who would later be TV’s Peter Gunn portraying Sephen Foster) and a sing-a-long of Stephen Foster songs. I suspect that the short was largely nostalgic to that audience of 70 years ago. I found the lyrics cringe-worthy.
I did learn one thing from the short: Foster probably earned a good deal of his money writing songs for minstrel shows (he was the first American to get rich writing popular songs). Many of his songs were written for and popularized by the Christy Minstrels, that most famous of all blackface groups, started in the 1840s by Edwin Pearce Christy.
In other words we’ve gone from something being the heart of mainstream popular culture 170 years ago to being nostalgic a century later to being horrid seventy years later.