In 1846, French Canadian-born A. M. A. Blanchet was named the first Catholic bishop of Walla Walla in the area soon to become Washington Territory. He arrived at Fort Walla Walla in late September 1847, part of the largest movement over the Oregon Trail to date. During the thirty-two years of Blanchet's tenure in the Northwest, the region underwent profound social and political change as the Hudson's Bay Company moved headquarters and many operations north following the Oregon Treaty, U.S. government and institutions were established, and Native American inhabitants dealt with displacement...