In 1876 and 1877, Captain W. P. Clark commanded a detachment of Indian scouts-including Pawnees, Shoshones, Arapahoes, Cheyennes, Crows, and Sioux-who conversed in sign language. They made requests, relayed information, and told stories with their hands, communicating in a language indispensable for quick understanding between Indians of different tribes. The scouts patiently taught Clark the sign system, which he patiently recorded in this book. Originally written in 1884 for use by the United States Army, The Indian Sign Language is far more than a grammar book or curiosity. Clark worked...