On 31 May 1850, the Holy See under Pope Pius IX established the Diocese of Nesqually (later spelled "Nisqually"), with its episcopal see in Vancouver in what was by then known as the Oregon Territory, and named Blanchet bishop of the new diocese.
On 23 January 1851, Blanchet established the existing St. James Church located at Fort Vancouver as his cathedral, renaming it St. James Cathedral [REF].