In this biography, Robert Carriker describes De Smet's love for the great American West and the native tribes who lived there, the Potawatomis, Flatheads, Coeur d'Alenes, Kalispels, Blackfeet, Yankton Sioux, and others to whom the Jesuit father carried Christianity. Soon the man called Black Robe became known throughout the mountains and plains as a man of peace and a friend of all Indians. Yet this book looks at De Smet as more than a mere courier of Christianity to the western tribes and an establisher of missions among the Indians. De Smet was also a fund raiser extraordinary for his order on both sides of the Atlantic Ocean as well as a writer of travel books read avidly by Catholics and non-Catholics alike. With the nearly quarter of a million nineteenth-century dollars he raised in his lifetime, and with the addition of his own family's funds, De Smet kept the Jesuits' underfunded western Indian missions alive.

Deeply sensitive to criticism by his fellow Jesuits, De Smet did not always enjoy community living. He felt most at home on the frontier, where he maintained his reputation as an affable companion on the trail, whether seated in a canoe or astride a mule, until his death in 1873.