The very first drawings Pratt ever made were of American Indians.

His love of the Indians, in particular those of the Northeastern United States (Iroquois and Mohawk) stayed with him for his whole life. Pratt created magnificent watercolors that were inspired by the Indian Wars and the War of Independence in North America.

He reached the peak of his graphic genius with the creation of Wheeling, a work dedicated to a city in Ohio that was plagued by clashes between the Native Americans and the white settlers.