When clawfoot tubs were created, they were created with an enameling cast iron surface. This was to make it feel smooth to the touch. When they were first created, they were advertised as a horse trough or hog scalder. Once they added the legs to the tub, it the became the bathtub. Soon they were made in quanity, as they were seen as being extremely sanitary and easy to clean. Which people felt prevented the spread of bacteria and diseases.
As time went on and World War I came to an end, most bathrooms were being filled with the usual toilet, sink and bathtubs. The bathtubs were mostly clawfoot tubs. Even that early though, most homes did not have any type of plumbing. So at first clawfoot tubs were used without having the plumbing that was added to them.
Eventually over time, this clawfoot tub changed into a built-in tub that had an apron up the front of it. With the style being enclosed, it made the maintenance of the bathroom even easier and more sanitary. It also offered more design options for the owner. Eventually our normal colored white, enameled clawfoot tub became a tub of many colors with the build on squirts.
Today people are shifting back to...