Samuel Johnson was born in Salem, Massachusetts, on October 10, 1822. He received an AB from Harvard in 1842 and graduated from Harvard Divinity School in 1846. He served the Church in Harrison Square (Third Unitarian Society) in Dorchester in 1851-52. In the next year he lectured on antislavery and preached wherever he could, including in Lynn, Massachusetts, where he became minister of the newly formed Lynn Free Church on May 29, 1853. He served this church until his retirement on June 26, 1870. He was never ordained, and the Lynn Free Church had no sectarian connection. He died in North Andover, Massachusetts, on February 19, 1882.
In the 1850s, he began to study and lecture on non-Christian religions. He wrote three separate books under the same title, Oriental Religions and Their Relation to Universal Religion, which covered India, China, and Persia. He is best remembered as a hymn writer ("City of God, How Broad, How Far" and "Life of Ages, Richly Poured" are perhaps the two that have had the most widespread and continuous use) and, with his HDS classmate Samuel Longfellow (1819-92), as a compiler of two influential hymnals, Book of Hymns (1846; enlarged edition, 1848) and Hymns of the Spirit (1864).
For more information, see the memoir by Samuel Longfellow in Lectures, Essays, and Sermons by Samuel Johnson (Boston: Houghton, Mifflin and Company, 1883. [Engraving (credit: P. T. Stuart) used as the frontispiece to Johnson's Lectures, Essays, and Sermons; an additional copy and more information in bMS 1446/99.]