The circus minstrel/vaudeville “buck dance” was always in a constant state of creative flux. It started off as plain “soft shoe” but today it's a form of tap and modern bucks have more metal taps than 'regular' tap shoes. Urban dance's “buck” is another beastie altogether.

Tap Dance Wiki:
“There are different brands of shoes which sometimes differ in the way they sound. "Soft-shoe" is a rhythm form of tap dancing that does not require special shoes, and though rhythm is generated by tapping of the feet, it also uses sliding of the feet (even sometimes using scattered sand on the stage to enhance the sound of sliding feet*) more often than modern rhythm tap. It preceded what is currently considered to be modern tap, but has since declined in popularity….”

“Tap dance has its roots in the fusion of several ethnic percussive dances, including African tribal dances, English clog dancing and Irish jigs; the relative contribution of different traditions is a point of disagreement among historians and dance scholars. Tap dance is believed to have begun in the mid-1800s during the rise of minstrel shows.”

*ie: Dixie's “scratch your gravel.”

Came across this thread poking around for Indian Intermezzo/Indianist Movement material. I wouldn't fault the latter's sincerity or effort but, I'd take any American Indian based popular entertaintment with a huge grain of Euro-American salt. The so-called 'Wild West Show' was probably the most popular of the lot.