The foxtrot originated around 1914 in vaudeville, by dancer Harry Fox. As part of his act Fox was executing trotting steps to ragtime music. Referred to as "Fox's trot" the dance was set to a broken rhythm (slow-slow-quick-quick). Bit by bit the dance moves changed, and with remarkable speed the foxtrot came to dominate the dancehalls and the music scene.
The foxtrot became the dance phenomenon of the 1920s. And the 1930s. And the 1940s. One could whirl around the dance floor, or one could execute the steps in the crush of a crowded venue, dancing (oh, dear!) close together and more or less in place. In those days, before television and computer games and tupperware parties, people danced. Dancehalls were everywhere. It might not be too great an exaggeration to say that dancehalls littered the landscape like Starbucks franchises in the 21st century. Irene and Vernon Castle, the exhibition ballroom dancers pictured here, were among the main celebrities of the day. In fact, by including the scandalous foxtrot in their routines, they sped its popularity.
The "St. James Infirmary" we know was partly shaped by the passion for dance that swept the nation and the world in the decades after the First World War. The song had already become something of a dancehall staple before it entered the recording studio, coming north with traveling musicians looking for work with the big bands. As musician Claude Austin said in 1931 (as transcribed by a court stenographer):
“Well, if there was any lapse in the dancing and the entertainment that was going on, the boss had a way of playing things that they used to call the Rocks, and the Rocks is the same thing as you call the Blues now, and this just happened to fall into that category. It was just one of those things that you did not need any music for, because there was no music for it, that they were able to pick up at the time while they were searching for something else to play of a popular trend, but at that time it was just a general piece we would play, ‘St. James Infirmary.’”