Thoreau's Civil disobedience (1849)
The Thoreau Reader: annotated works of Henry David Thoreau.
Joseph F. Kobylka. Iconoclastic Individualism — Thoreau (YouTube video; part 2; part 3). In Cycles of American Political Thought, lecture 18.
Emerson's Self-reliance (1841)
Seneca Falls Declaration (1848), modeled on the Declaration of Independence.
Whitman's Song of myself, 34