Navigation Map
This portion of a map used by Lts. Oakley Kelly and John Macready for navigation on their Transcontinental Flight on May 2-3, 1923, demonstrates one method of early aerial navigation. This commercial map produced by Rand McNally showed the rail lines, and the colored pencil marks indicate the westerly route they took across Illinois. Note that their flight followed the railroad tracks between Terre Haute, Ind., and St Louis, Mo., with the estimated times of arrival marked in 10-minute increments. (U.S. Air Force)