When the United States Army realized it could not satisfactorily meet its World War I logistical needs by railroad alone, it organized truck convoys to supplement them, with the first run in 1917 from Toledo, Ohio, to Baltimore, Maryland. Following the two-month ordeal of the U.S. Army Transcontinental Motor Convoy in 1919, the need for better infrastructure became even clearer.
In 1921, Thomas H. MacDonald, the newly appointed head of the Bureau of Public Roads, requested the Army provide it with a list of roads of "prime importance in the event of war". MacDonald had the Geological Survey and later his own staff painstakingly draft out the details of the Army's request, and presented the sum of these drawings in a massive 32-foot (9.8 m)-long map to Army War Plans. General of the Armies John Pershing himself reported the results back to Congress in 1922, with the proposal becoming known as the "Pershing Map".
Most of the 78,000 miles (126,000 km) of roads requested were eventually built, with a number of routes becoming interstate highways. The proposal emphasized coastal and Mexican border defense and industrial needs of the time rather than economic development, with high priority routes going to such checkpoints as Sault Ste Marie, Michigan, yet bypassing nearly the entire Deep South. Professor Steven Dutch points out that this routing reflected the technology and needs of the post-World War I military. Coal fields and iron ports were critical for steel production, but the then-nascent oil fields in West Texas and Oklahoma were not yet important, and with little infrastructure, southern Florida was not a priority since any army landing there would have had no method to advance northwards.
- Weingroff, Richard F. (Spring 1996). "Milestones For U.S. Highway Transportation and the Federal Highway Administration". Public Roads. Washington, DC: Federal Highway Administration. 59 (4). Retrieved May 23, 2012.
- McNichol, Dan (2006). The Roads That Built America: The Incredible Story of the U. S. Interstate System. New York: Sterling Publishing. p. 62. ISBN 9781402734687.
- Dutch, Steve (June 2, 2010). "Military Impacts on the Environment". University of Wisconsin-Green Bay. Retrieved May 23, 2012.