On 28 July 1846, while a canon in Montreal, A.M.A. Blanchet was appointed bishop of the new Diocese of Walla Walla in the Oregon Country. Blanchet was to follow his brother, who had gone to the Oregon Country in 1838 to set up a Catholic church presence there, and was the bishop of the Diocese of Oregon City. Blanchet was ordained bishop on 27 September 1846 by Archbishop Ignace Bourget at Saint-Jacques Cathedral in Montreal. He left for Oregon on 4 March 1847 and arrived in Walla Walla on 5 September. The killing of Protestant missionaries in the Whitman massacre on 29 November 1847 led to an uneasy relationship among Blanchet, the native Cayuse people, and the United States government, and as a result Blanchet retreated to St. Paul in the Willamette Valley. On 31 May 1850, the Holy See under Pope Pius IX established the Diocese of Nesqually, with its episcopal see in Vancouver in what was by then known as the Oregon Territory, and named Blanchet bishop of the new diocese. Three years later the Walla Walla diocese was completely eliminated and much of its territory transferred to the new Nesqually diocese.
Bishop of Nesqually
On 23 January 1851, Blanchet established the existing St. James Church built by his brother François and Modeste Demers at Fort Vancouver as his cathedral, renaming it St. James Cathedral. In 1853, the diocese's territory became part of the Washington Territory. In 1868, Francis X. Prefontaine, a young priest and fellow Quebec native, requested Blanchet's permission to build a church building near Pioneer Square in bustling Seattle to support the city's first Catholic parish, Our Lady of Good Help, which he had recently established. Blanchet believed that Seattle was a lost cause, but nevertheless he gave the priest permission to build a church as long as Prefontaine would raise the money for it himself and it would cost the diocese nothing. Prefontaine eventually raised enough money to build a church, and in 1869 he opened Seattle's Catholic church. The Church of Our Lady of Good Help no longer stands but its namesake statue of the Virgin Mary was saved and now stands in the cathedral chapel under the title of "Our Lady of Seattle."
Retirement and death
Blanchet retired as bishop on 23 December 1879, at age 82, and was named titular bishop of Ibora. He continued to live in the Diocese of Nesqually in his retirement, and died in Vancouver on 25 February 1887.
Legacy and veneration
Blanchet's first cathedral at Fort Vancouver was succeeded by a new St. James Cathedral in Vancouver in 1885; the original cathedral burned down in 1889. In the early 20th century, Francis X. Prefontaine, who years earlier had requested Blanchet's permission to build a church in Seattle, convinced Bishop Edward O'Dea to move the episcopal see of the Diocese of Nisqually to Seattle, and in 1903 the diocese was renamed the Diocese of Seattle. The cathedral O'Dea built in Seattle retained the St. James Cathedral name of Blanchet's original cathedral. Bishop Blanchet High School in Seattle's Green Lake neighborhood is named for A.M.A. Blanchet. In 1955, it was discovered that Bishop Blanchet's body is incorrupt.
