Thoreau was able to view the exploits of the great explorers of the continent metaphorically, as parallel to the exploration by the individual of the world within himself. He wrote in the conclusion to Walden:
What does Africa, — what does the West stand for? . . . Is it the source of the Nile, or the Niger, or the Mississippi, or a North-West Passage around this continent, that we would find? . . . Be rather the Mungo Park, the Lewis and Clark and Frobisher, of your own streams and oceans; explore your own higher latitudes. . . .
Though it might be considered metaphorically, however, through its consequences, expansion presented moral difficulties that the Transcendentalists could not ignore.
Most of the New England Transcendentalists — Thoreau and Emerson among them — supported the abolition of slavery. They were, for several reasons, predisposed to take up this cause. Dr. William Ellery Channing, the "father of Unitarianism" and a source of inspiration, wrote a treatise titled Slavery (1835) and frequently wrote and spoke in favor of abolition. Moreover, Boston was a center of antislavery activity. Radical abolitionist William Lloyd Garrison established the periodical The Liberator in Boston in 1831, and was a founder of the New England Anti-Slavery Society there in 1832.
But the Transcendentalists also felt some ambivalence about ardent abolitionists and others who sought to reform society through political and legal action. Transcendentalism stressed the reform of society through perfection of the individual from within, not through external social means. At times, both Emerson and Thoreau wrote disparagingly of reformers.
Despite their reservations, however, Emerson, Thoreau, Alcott, Theodore Parker, and others were important in the antislavery movement. Emerson delivered his first antislavery address in Concord in 1837, in response to the murder of abolitionist publisher Elijah Lovejoy in Alton, Illinois. Emerson delivered his passionate An Address . . . on the Anniversary of the Emancipation of the Negroes in the British West Indies in 1844, in the Concord courthouse. During the 1840s and 1850s, he spoke out frequently against slavery, appearing with Garrison and other leaders of the movement. The Fugitive Slave Law enraged Emerson, and he advocated disobeying it.
