Lieutenant Revere of the U.S. Navy acknowledged that he based this map on the published maps and charts of the San Francisco Bay area by Frederick William Beechey of the British Royal Navy. Originally published by the Admiralty in 1833, Beechey's efforts resulted from a thorough survey he and the men of H.M.S. Blossom conducted in 1826 and 1827 by permission of Mexican authorities. Beechey's efforts influenced all subsequent charts of the area for many years. Revere's map is on a scale of 30 miles to 5-3/4 inches and shows additional ranchos and towns. It was reproduced by the lithography firm of William Endicott & Co. of New York. See Neal Harlow, The Maps of San Francisco Bay from the Spanish Discovery in 1769 to the American Occupation (San Francisco: The Book Club of California, 1950), pp. 63-71, 118.
