A short article entitled "Ivory and its Uses" describes the ivory used
by Pratt, Read and Co. of Ivoryton, Connecticut, who manufactured
keyboards for pianos and organs.  Excerpt:

  Ivory is of two types: hard and soft. The hard ivory came from India.
  Soft ivory, which was used for making ivory piano keys, came from
  Africa.  The softest and best quality of ivory tusks was imported
  to the United States where Pratt, Read and Co. of Ivoryton was the
  largest buyer and manufacturer.

Several more interesting short articles about Ivoryton and its commerce
are at http://www.ivoryton.lioninc.org/ 

Robbie Rhodes, MMD