Dana was a student at Harvard College when he developed a case of measles that left his eyesight so weak he had to take on an outdoor life free of studying. As a result he signed on a brig and spent 16 months on board plying the coast of California (January 1835-May 1936).
His observations about San Pedro, which was to become the harbor of Los Angeles, are particularly pithy:
The desolate place...We all agreed that it was the worst place we had yet seen.... there was no sign of a town. What had brought us into such a place we could not conceive...we lay exposed to every wind that could blow. I learned to my surprise that the desolate looking place was the best place on the whole coast....and about thirty miles in the interior...was the Pueblo de Los Angeles.His observations were published in 1840 in his Two Years Before the Mast.