"Two Years Before the Mast" is a memoir by the American author Richard Henry Dana, Jr., published in 1840, having been written after a two-year sea voyage starting in 1834. Dana's book was one of the few books in existence that described California, adding greatly to the book's readership as well as Dana's renown and legacy. When he returned to San Francisco in 1859 he was treated as a minor celebrity. To this day the book is regarded as a valuable historical resource describing 1830s California.