You are probably right that most ivories were for home use. However, it would have been in the homes of the well to do. We know ivories were used in some of the illegal gambling joints in Manhattan in the 1880s to 1910s. There are ivories from the paddlewheel boats traveled the Mississippi.

I would say that from 1860 to the early 20th century a good percentage of high class gambling joints used ivory. Also many of the old western joints used ivory.