(Understanding that at that time "gay" was used in the sense of happy/jolly, not homosexual)
Where did the early twentieth century nostalgia in America for the 1890s come from? Was it simply a transposition of European nostalgia for the Belle Epoque? Or did people just really love Grover Cleveland and ragtime?
I don't exactly address what was so "gay" about the Gay Nineties, but I do have a previous answer on this nostalgia, if you're interested: I've read on this sub that people used to be nostalgic for the 1890's during the decades that followed. What about this time were they nostalgic about? and what was the aesthetic like in terms of culture and politics and business?