1845 Term Manifest Destiny first used in anonymous piece in July–August issue of The United States Magazine and Democratic Review, probably by John L. O'Sullivan
Texas annexed by United States
Frémont expedition to explore area around Great Salt Lake in Utah
George Henry Evans founded National Reform Association for benefit of labor
Brook Farm periodical The Harbinger began publication
Margaret Fuller's Woman in the Nineteenth Century published
Thoreau built and moved into cabin at Walden Pond in Concord (remained until 1847)
1846 War with Mexico declared
Mormon migration from Illinois to Utah began
Smithsonian Institution founded in Washington, D.C.
Hawthorne's Mosses from an Old Manse published
Thoreau jailed for refusal to pay poll tax in protest against slavery
1847 Massachusetts Quarterly Review founded
Emerson's first volume of poetry, Poems, published
Longfellow's Evangeline published
1848 Whig Zachary Taylor elected to presidency
Mexican War ended; Mexico surrendered much territory to United States
Gold rush began
Lucretia Mott and Elizabeth Cady Stanton organized first Seneca Falls women's convention
New York State granted property rights for women commensurate to those for men
Boston Female Medical School (first medical school for women in America) opened
Industrial utopian community founded at Oneida, New York
1849 Amelia Bloomer's The Lily began
Elizabeth Palmer Peabody published Aesthetic Papers, including Thoreau's "Resistance to Civil Government" (later known as Civil Disobedience)
Thoreau's A Week on the Concord and Merrimack Rivers published
