The annotation on this map reads, “Used in laying out route for flight from San Diego to St. Louis to New York to Paris, 1927” and is signed C.A. Lindbergh. The map bears the official stamp: “CORRECTED THROUGH NOTICE TO MARINERS NO 25 JUNE 19’26 HYDROGRAPHIC OFFICE NAVY DEPARTMENT.” Charles Lindbergh (1902–74) was the American aviator who made the first nonstop solo flight across the Atlantic Ocean on May 21–22, 1927. Because Lindbergh relied on the dead-reckoning method of navigation, this map would have been useful in determining the magnetic declination (the angular difference between magnetic north and true north).