In 1794, Joseph Priestley left England to escape religious and political persecution. Although a world-renowned theologian, philosopher, and scientist, he was, for years, subjected to increasingly bitter criticism by his countrymen. His unorthodox religious beliefs and his ardent support of the American and French revolutions made him a target of the supporters of the English monarchy and the Church of England. The persecution culminated in the destruction of his house, library, and laboratory by a mob which also threatened his life.

At age 60, he arrived in America and settled in Northumberland, Pa. He built a house (which has been preserved) and lived out the last ten years of his life here. In spite of the deaths of his wife, Mary, and youngest son, Harry, and his failing health, his time in Northumberland was fairly tranquil and productive. He conducted Unitarian services in his home and in a nearby schoolhouse and managed to attract a small group. This was the first congregation in the United States to call itself “Unitarian”(1) but it was not as successful as he would have liked when he died in 1804.

One son, William, moved to Louisiana and the eldest son, Joseph, Jr. moved back to England in about 1813, which ended the Priestley presence in Northumberland for that time. Fortunately, a grandson, Joseph Rayner Priestley, returned to Northumberland, at age 19, and married his childhood sweetheart, Frances Dundas Biddle.(2)  They had a large family and were members of the Unitarian congregation formed by Rev. James Kay from the remnants of Priestley's original group. For several years they met in the Union church in Northumberland, which they shared with three other denominations.