On August 14, 1834, nineteen-year-old Richard Henry Dana Jr. made his way to Boston Harbor in search of a two-masted brig called the Pilgrim. An archetypal Brahmin—dad was a poet and essayist, granddad had been chief justice of the Massachusetts Supreme Court, great-granddad was one of the original Sons of Liberty—Dana had been a promising student at Harvard College until measles inflamed his corneas and he could no longer read without pain. He resolved to effect a “cure, if possible, by an entire change of life.” Discarding the dress coat and silk cap of an undergraduate, he donned the duck trousers and tarpaulin hat of a sailor.

The remedy worked, but even more valuable were the experiences that Dana, who was born 200 years ago this August, turned into Two Years Before the Mast, one of America’s first literary classics. An astonishingly effective memoir of life as an ordinary seaman quartered “before the mast” in the squalid space below decks, the book, a sensation in its own time, is a model of reportage, rife with the nautical jargon of a specialist and an anthropologist’s descriptive mastery of life aboard ship and in the Pilgrim’s then-exotic ports of call. It would influence generations of readers and writers and remains a mainstay on American reading lists.

Dana’s voyage took him into the south Atlantic Ocean, around Cape Horn, and to Alta California, then a sparsely settled province of Mexico. The ship’s mission was to obtain cattle hides from ranchers at San Diego, Santa Barbara and other points along the coast. A naif not yet prejudiced by experience, Dana shares something new on every page: whale songs and icebergs, smashing storms, the captain’s violent discipline, the total silence of the sea at night. His vivid writing lacks literary self-consciousness and easily transmits his feelings. When a shipmate falls overboard and dies, Dana’s pain is tangible. “At sea, the man is near you—at your side—you hear his voice, and in an instant he is gone, and nothing but a vacancy shows his loss....It is like losing a limb.’’

In California, Dana mastered the art of carrying the wide, flat, heavy hides atop his head. From one steep bluff, which Dana called “the only romantic spot on the coast,” the sailors pitched the hides onto the beach like giant Frisbees; that spot, some 60 miles south of contemporary Los Angeles, is today a city called Dana Point. But it wasn’t all work: Dana went to cockfights, ate frijoles and watched performances of the fandango. A decade later, forty-niners rushing to California carried Two Years Before the Mast as a guidebook.

Dana arrived back in Boston two years older and, in his own words, “a ‘rough alley’ looking fellow, with duck trousers and red shirt, long hair, and face burnt as dark as an Indian’s.’’ He was changed inside as well. He returned to school and became a maritime lawyer and advocate for the rights of sailors and the downtrodden everywhere. He defended fugitive slaves and their rescuers; later, he served as a U.S. attorney.

His book influenced, among others, Herman Melville, who called it “unmatchable.” Dana encouraged Melville to ground his whaling story in fact, but Melville was concerned that such an approach could be tedious. “It will be a strange sort of book, tho’, I fear,” he wrote to Dana. “Blubber is blubber you know; tho’ you may get oil out of it, the poetry runs as hard as sap from a frozen maple tree....Yet I mean to give the truth of the thing, spite of this.” Of course, Moby-Dick is celebrated for just that. And scholars have found Dana’s imprint in the heroes of later American works about young men who leave home to find themselves, from Huck Finn to Holden Caulfield to Hemingway’s Nick Adams.

Dana was fortunate to establish a thriving legal career. Two Years Before the Mast was published in 1840, and though it sold 200,000 copies in its first decade, he’d turned down a deal that would have earned him a 10 percent royalty. Instead he settled for a flat $250 (not quite $7,000 today), plus 24 free copies.