MacEachern was born in Kinlochmoidart, Scotland, the son of Hugh Bàn MacEachern and Mary MacDonald. He became a protégé of Bishop Hugh MacDonald, vicar apostolic of the Highland District of Scotland, and, when his family Prince Edward Island in 1772, 13-year-old Angus stayed behind to study for the priesthood in the secret Highland Catholic college at Buorblach near Morar Station. His seminary training was received in Spain since education was then denied Catholics in England, Ireland and Scotland, and professional training, in particular, training for the priesthood, had been expressly forbidden under pain of death by the penal laws against Catholics. MacEachern arrived on Prince Edward Island, then a British colony in North America known as St. John's Island, in 1790 as a young missionary, joining his emigrant family. MacEachern, who would later be recognized as firmly placing Catholic roots in the colony as well as throughout the Maritimes, travelled endlessly in the area as a priest. He was fluent in English, French, and Gaelic, therefore permitting him to minister to a variety of different cultures in the region. In 1816, while serving as priest in Charlottetown, MacEachern was advised by a visiting Bishop from Quebec to build a church inthe city and dedicate it to St. Dunstan, the Archbishop of Canterbury. The church was the first of several that would occupy the lot where the present cathedral stands today. In 1819, MacEachern became Vicar General for most of the Maritimes as well as becoming a Bishop, and by the 1820s he was convinced that the only way to renew the area's religious beliefs was independence from the neglectful Archdiocese of Quebec. MacEachern finally got his wish when the Diocese of Charlottetown, comprising Prince Edward Island, New Brunswick, and the Magdalen Islands was created in 1829, with MacEachern appointed as its first Bishop. On 30 November 1831, MacEachern founded St. Andrew's College. Located in his large home in St. Andrew's, PEI, the first Catholic College in the Atlantic provinces offered preliminary training for seminarians. Much loved by his people, Bishop MacEachern died in 1835 in Canavoy, Prince Edward Island. His funeral took place in St. Andrew's Church, with burial in the church basement. His remains now lie in the crypt of a nearby chapel.
