Appleton's Encyclopedia tells us:
HARRIS, Thomas Lake, spiritualist, born in Fenny Stratford, England, 15 May, 1823. He came with his father to the United States, settled in Utica, New York, and began to write for the press before his seventeenth year, soon acquiring some celebrity as a poet. He renounced Calvinism in early manhood, and, entering the ministry of the Universalist church, removed to New York, becoming pastor of the 4th Universalist society. Failing health compelled him to resign this charge, and in the next year he organized an "Independent Christian society," to which he ministered until the spiritualistic movement of 1850. He then joined a community at Mountain Cove, Virginia, and after a few months of investigation declared himself a convert to the new faith, and entered on a lecturing tour throughout the United States. On his return to New York he organized a society, and established a spiritualistic journal. He went to Great Britain in 1858, and lectured in London, Edinburgh, Manchester, and Glasgow, returning with a few enthusiasts who participated in his views, and retired to a farm in Dutchess county, New York As the community increased, he purchased small farms near the village of Amenia, established a national bank, engaged in milling and other business, and reorganized the society, which was henceforth known as the "Brotherhood of the New Life." He went to Europe in its interests in 1866, and the next year removed to Portland, New York, where he purchased large farms. No property was held in common, but members of the society were permitted to hold real estate, and cultivate it on their own account. The authority of the Scriptures and the marriage relations were held sacred, there was no written creed or form of government, and the system appeared to combine the doctrines of Plato in philosophy, Swedenborg in spiritual science, and Fourier in sociology. It numbered more than 2,000 members, some residents of the community, and other citizens of foreign nations. At one time Lady Oliphant and her son, Laurence Oliphant, several Japanese high in official rank, and two Indian princes were residents of this community. Several years ago it was abandoned by Mr. Harris, who went to California, and his lands were purchased by Mr. Oliphant. Mr. Harris edited a spiritualistic journal for some time, entitled "The Herald of Light," and has published, among numerous poetical and prose works descriptive of his philosophy, "The Epic of the Starry Heavens" (New York, 1854); "Modern Spiritualism " (1856); "A Lyric of the Morning Land" (1854); "A Lyric of the Golden Age" (1856); "Truth and Life in Jesus" (1860); and "The Millennium Age" (1861).
There is another writeup in the 1911 edition of the Encylopedia Britannica
Arthur Cuthbert, an almost lifelong friend, wrote The Life and World-Work of Thomas Lake Harris. Glasgow, 1908, 413 pp. (excerpted chapters)
His papers are held at the Columbia University Rare Books and Manuscript Library
Aims and issues of the new church (sermons). Glasgow : James Fowler, 1863, 282 pp.
The Arcana of Christianity; an Unfolding of the Celestial Sense of the Divine Word through T. L. Harris: Vol. I, Genesis, New York, New Church, 1858; Vol. II, Matthew, published part in The Golden Child and part in The Herald of Light, 1859 and 1878; Vol. III, The Apocalypse, New York and London, Brotherhood of the New Life, 1867; Appendix, The Song of Satan, New York, New Church, 1858.
Battle Bells, Fountain Grove. 1891, 85 pp.
The Breath of God with Man; an Essay on the Grounds and Evidences of Universal Religion. New York and London, Brotherhood of the New Life, 1867
Bridal Hours: Lyrical Utterances of the Two-in-One. Fountain Grove, 1878, 60 pp.
The Brotherhood of the New Life; Its Fact, Law, Method and Purpose. Fountain Grove, 1891, 15 pp.
The concept of the word. Fountaingrove, Santa Rosa, Calif., 1898, 75 pp.
Conversation in Heaven; a Wisdom Song. Fountain Grove, 1894, 218 pp.
Declarations of the Divine One-Twain. Fountain Grove, 1882.
An Epic of the Starry Heaven. New York, Partridge and Brittan, 1854, 210 pp.
Extemporaneous Sermons Preached in the Marylebone Institute, London, in the Year 1860, by Thomas L. Harris. Collated and edited by Thomas Robinson, Manchester, Ratcliffe, 1879, 311 pp.
First Book of the Christian Religion. New York, New Church, 1858, 175 pp.
God's Breath in Man and in Humane Society. Fountain Grove, 1891, 314 pp.
The Golden Child; a Daily Chronicle&emdash;5 vols., Fountain Grove, 1878; Vol. I, Songs of Fairyland; Vol. II, Wisdom in Council; Vol. III, Gifts of Innocence; Vol. IV, Summaries and Conclusions; Vol. V, The Concept of the Word.
The Great Republic; a Poem of the Sun. New York and London, Brotherhood of the New Life, 1867, 261 pp.
The Holy City and the Light Therein. Fountain Grove, 1880, 229 pp.
Hymns of Spiritual Devotion for the New Christian Age, 2 vols.: Vol. I, New York, New Church, 1859, 5th ed. 1861; Vol. II, bound with 5th ed. of Vol. I, 1861, 302 pp. (written under spiritual agency)
Hymns of the Two-in-One; for Bridal Worship in the Kingdom of the New Life. Brocton, Brotherhood of the New Life, 1876, 48 pp.
In Dawnrise; a Song of Songs. Fountain Grove, 1896, 136 pp.
The Joy Bringer, Fifty-Three Melodies of the One-in-Twain. Fountain Grove, 1886, 79 pp.
Juvenile depravity and crime in our city. New York, C.B. Norton, 1850, 15 pp.
Lecture on spiritual manifestations, past, present, and future. Boston, G.C. Rand, 1853, 24 pp.
The Lord: the Two-in-One, Declared, Manifested and Glorified. Fountain Grove, 1876, 148 pp.
The Luminous Life. Fountain Grove, 1882.
Lyra Triumphalis, People Songs, Ballads and Marches. Fountain Grove, 1891, 53 pp.
A Lyric of the Golden Age. New York, Partridge and Brittan, 1856, 381 pp.
A Lyric of the Morning Land. New York, Partridge and Brittan, 1854; first European edition, Glasgow, Thomson, 1869, 172 pp.
The Marriage of Heaven and Earth, Verified Realities. Glasgow, Pearce, 1903, 287 pp.
The Millennial Age; Twelve Discourses on the Spiritual and Social Aspects of the Times. Manchester, Ratcliffe, 1860.
Modern spiritualism, its truths and its errors, a sermon. London, 1860, 88 pp.
The narrow way of attainment, eight lectures. Applegate, Cal., Esoteric Pub. Co., 1895, 140 pp.
The New church: its spirit, scope and mission, a lecture. Manchester, Johnson and Rawson, 1860, 30 pp.
The New Jerusalem, the crown of churches and the glory of the world, a serman. London, W. White, 1860, 24 pp.
The New Republic; a Discourse of the Prospects, Dangers, Duties and Safeties of the Times, Originally Addressed to the Socialists of America but of Universal Application in Principle. London, E. W. Allen, 1891, 75 pp.
The power and glory of the church of Christ, a sermon. London, W. White, 1860 37 pp.
Regina; a Song of Many Days. London, W. White, 1860. 239 pp.
Second book of fragments. [Santa Rosa? Calif., Fountaingrove Press?], 1897, 88 pp.
The Song of Theos; a Trilogy. Glasgow, Pearce, 1903. Vol. I, Easter; Vol. II, Emancipations; Vol. III, Avatar, 120 pp.
Star Flowers; a Poem of the Woman's Mystery. Nine Cantos, Fountain Grove, 1886-1887, 125 pp.
The Triumph of Life, "In Hoc Signo Vinci" 1902, Theos-Thea, In Lilistan-Fourth Dimension. Glasgow, Pearce, 1903, 179 pp.
Truth and Life in Jesus; Sermons Preached in the Mechanics' Institution, Manchester, 1859. London, W. White, 1860, 199 pp.
Veritas; a Word Song. Glasgow, Pearce, 1910, 192 pp.
A Voice from Heaven. Fountain Grove, 1879, 66 pp.
The Wedding Guest, Jesus-in-Yessa. Five Visits: Vols. I-IV, Fountain Grove, 1877-1878; Vol. V, Fountain Grove, 1882.
White Roses for the Pall. 2 Vols., Glasgow, Pearce, 1910.
The Wisdom of Angels. New York, New Church, 1857, 218 pp.
The Wisdom of the Adepts, Esoteric Science in Human History. Fountain Grove, 1884, 527 pp.
Cuthbert, Arthur A., The Life and World-Work of Thomas Lake Harris. Glasgow, 1908, 413 pp. (excerpted chapters)
Hardinge, Emma (Mrs. Britten), "Spiritual Movements&emdash;Mountain Cove," in Modern American Spiritualism; a Twenty Years' Record of the Communion between Earth and the World of Spirits. New York, 1910, pp.207-2I7.
Hinds, William Alfred, "The Brotherhood of the New Life," in American Communities, Oneida, N.Y., 1878, Pp. 141-151.
M'Cully, Richard, The Brotherhood of the New Life and Thomas Lake Harris. Glasgow, 1893.
Martin, Robert N., and Ernest Buckner, "The Harris Community," in The Centennial History of Chautauqua County, Jamestown, N.Y., Chautauqua History Co., 1904.
Oliphant, Laurence, Masollam; a Problem of the Period: a novel. 3 vols. Edinburgh and London, Blackwood, 1886.
Oliphant, Margaret Oliphant W., Memoir of the Life of Laurence Oliphant and of Alice Oliphant, His Wife. 2 vols., Edinburgh and London, Blackwood; New York, Harper, 1891.
Respiro (C. M. Berridge), The Brotherhood of the New Life; an Epitome of the Works and Teachings of Thomas Lake Harris. 16 vols. projected and announced, of which 12 vols. were published: 1st and 2d eds. Vols. I-V, London, E. W. Allen, 1896-1897; 3d ed. (so called) Vols. I and III, revised, and Vols. VII, X, XI, XII, XIII, XIV, XVI, Glasgow, Pearce, 1907-1917- Vol. I, Internal Respiration, 1896, 1914; Vol. II, The Impending World Crisis, 1897; Vol. III, The Divine Incarnation, 1897, 1917; Vol. IV, The Second Advent, 1897; Vol. V, The Man, the Seer, the Adept, the Avatar: (A), T. L. Harris, the Man, (B), T. L. Harris, the Seer, 1897 (the title of Vol. V was announced as "The Servant of Humanity; or, T. L. Harris, the Man"); Vol. VI, announced as "The Lifting of the Veil; or, T. L. Harris, the Seer"; Vol. VII; The Adept of the Logos, 1911; Vol. VIII, announced as "The Messenger of God; or, T. L. Harris, the Avatar of the Cycle"; Vol. IX, announced as "The Lifting of the Veil; or, T. L. Harris, the Seer"; Vol. VII, The Vol. X, The Evolution of the Cosmos, 1910; Vol. XI, The Orbs of the Universe, 1908; Vol. XII, The Inspired Word, 1915; Vol. XIII, The Secret of Satan, 1907; Vol. XIV, Re-Tricarnation, 1912; Vol. XV, announced as "Arch-Naiural Angelhood"; Vol. XVI, Counterparts, 1909.
Schneider, Herbert and George Lawton, A Prophet and a pilgrim. Columbia Univ Press, NY, 1942. 589 pp