Henry David Thoreau's manuscripts, arranged in meticulous order at his death, were in the following decades widely dispersed. For details, see William Howarth, The Literary Manuscripts of Henry David Thoreau (Columbus: Ohio State University Press, 1974). Various manuscript versions of Walden and other manuscripts, letters, poems, and journal materials are housed at the Henry E. Huntington Library, San Marino, California; the largest collection of letters is housed at the Berg Collection and Manuscript Division of the New York Public Library; many letters and some essay drafts are held in Harvard University 's Houghton Library; most of Thoreau's journals, as well as his Indian and Canadian notebooks, are housed in the Pierpont Morgan Library in New York City. Other important collections are the Morris Library at Southern Illinois University, Carbondale, Illinois; the Concord Free Public Library, Concord, Massachusetts; the John Hay Library, Brown University, Providence, Rhode Island; the Miriam Lutcher Stark Library at the University of Texas, Austin; the Alderman Library at the University of Virginia, Charlottesville; and the Abernathy Library at Middlebury College, Middlebury, Vermont.
Thoreau also remained a devoted abolitionist until the end of his life. To support his cause, he wrote several works, including the 1854 essay "Slavery in Massachusetts." Thoreau also took a brave stand for Captain John Brown, a radical abolitionist who led an uprising against slavery in Virginia. He and his supporters raided a federal arsenal in Harpers Ferry to arm themselves in October 1859, but their plan was thwarted. An injured Brown was later convicted of treason and put to death for his crime. Thoreau rose to defend him with the speech "A Plea for Capt. John Brown," calling him "an angel of light" and "the bravest and humanest man in all the country."