John Thayer (priest)

John Thayer (1758-1826) was an American Catholic priest and missionary, known for his conversion from Congregationalism to Catholicism and his subsequent missionary work in the United States and Europe.

Born in Boston, Massachusetts, Thayer was initially raised in the Congregationalist faith. He graduated from Yale College in 1776 and served as a chaplain in the Continental Army during the American Revolutionary War. Following the war, he traveled to Europe, where he encountered Catholicism and became increasingly drawn to its doctrines and practices.

In 1783, while in Rome, Thayer converted to Catholicism and was subsequently ordained a priest in 1789. He returned to the United States in 1790, becoming one of the first American-born Catholic priests. He dedicated himself to missionary work, particularly among Protestants, attempting to convert them to Catholicism. He faced considerable opposition and prejudice due to the prevailing anti-Catholic sentiment in the United States at the time.

Thayer's missionary activities were not confined to the United States. He also spent time in England and Ireland, preaching and writing in defense of the Catholic faith. He published several controversial pamphlets and books, explaining and defending Catholic doctrines, including "An Account of the Conversion of the Reverend Mr. John Thayer, Formerly a Protestant Minister of Boston, in North America" (1787).

Later in his life, Thayer returned to Limerick, Ireland, where he died in 1826. His efforts, while met with resistance, contributed to the growth of the Catholic Church in the United States during its early years. He is remembered for his zeal, his dedication to his newfound faith, and his role in the early American Catholic Church.