Except on Indigenous Sweat Lodges:
Washington D.C July 7th, 1884.
Lieut.- General P. H. Sheridan,
Sir,—I have the honor to submit herewith, in compliance with your instructions, a work upon
the Sign Language of the Indians living within the territory of the United States, with some
account of their tribal histories and race peculiarities.
This work is based upon my own observations, made among the Indians themselves during a period of more than six years, supplemented by a careful study of the principal authorities on Indian habits and customs.
Your obedient servant,
W. P. CLARK,
Captain Second Cavalry