FreightWaves Classics has covered the history of the Interstate Highway System in previous articles. In those articles, it was noted that the U.S. Army organized the Motor Transport Corps Convoy to cross the United States. The convoy’s mission was to test the usefulness of existing roads in case of national emergency.

The convoy began its trip on July 7, 1919; 79 Army vehicles left Washington, D.C. to drive to San Francisco along the Lincoln Highway. The Lincoln Highway was one of the nation’s first transcontinental routes and was 3,389 miles long. The convoy included nearly 300 soldiers and U.S. War Department observers (among them was Lt. Col. Dwight D. Eisenhower, who would play a key role in the development of America’s highways later in his life). 

The 1919 convoy in Wyoming. (Photo:

At that time, sections of the Lincoln Highway consisted of dirt and gravel tracks – and in some locations the highway’s “pavement” was loose sand. Poor weather and steep grades made the road impassable at times. Numerous bridges (particularly in the western U.S.) were demolished and rebuilt to allow the convoy’s heavy vehicles to proceed. The trip to San Francisco Bay took 62 days; and the convoy’s average speed was just 6.07 mph.

As the number of automobiles and trucks increased rapidly, the trip pointed out the poor conditions of the nation’s roads. The significant time that the convoy took to make the trip, the extremely bad condition of the “highway,” and the many mechanical breakdowns were all evidence that significant improvements needed to be made. 

Beginnings of a national highway system

Following the convoy’s cross-country trip and its reports about the poor state of U.S. roads, the Bureau of Public Roads (a precursor to the Federal Highway Administration) commissioned General John J. Pershing, the highest-ranking member of the U.S. Army, to draw a map to give the government a clearer understanding of which roads in the United States were the most important in the event of war.

General Pershing. (Photo:

Under Pershing’s leadership, the Army complied with the Bureau’s request. On this date in 1922, General Pershing signed the “Pershing Map,” which outlined a system of national routes developed by military authorities to be of special importance to national defense. Those who created the map used the convoy’s reports from 1919 to help draw a detailed network of interconnected primary highways the Army felt were essential for national defense. 

The 1922 Pershing Map. (Image: Federal Highway Administration)

Therefore, the Pershing Map was the first official topographic road map of the United States. It included 78,000 miles of roads with an emphasis on coverage in coastal areas and border crossings considered necessary for national defense.

The War Department’s general position was that a system designed to serve the nation’s industrial and commercial needs could adequately serve the military’s needs as well.

Additional road surveys demonstrated the need for a federally maintained highway network that could support national defense and interstate commerce. The Pershing Map was an early model for nationwide, connected highways, surface roads, and feeder routes. While it was supplanted by later planning, many of the routes drawn on the Pershing Map are interstate highways today.

The Pershing Map led to major road construction projects throughout the 1920s, which until the stock market crash in late September 1929, was a prosperous decade. Projects such as the New York parkway system were built as part of a new national highway system. Automobile and truck traffic continued to increase; planners recognized a need for an interconnected national highway system to provide an alternative to the existing, largely non-freeway system of U.S. roadways. 

A 1947 map shows a plan for interstate highways. Many of the routes are very similar to those of the Pershing Map, which was created 25 years previously. (Map: Federal Highway Administration)

Great Depression and World War II slow road-building

However, despite support from the Army, the War Department and some in Congress, overall support for the costly public works project remained low. Planning for such a system continued throughout the 1930s; however, the impact of the Great Depression and then World War II meant that little of the planning was implemented. 

In 1942 (almost 20 years after the Pershing Map was created) President Franklin D. Roosevelt established the National Interregional Highway Committee to investigate an interstate road network’s viability. The committee released its report in 1944. It refined concepts found in the Pershing Map and emphasized transcontinental, long-haul roads. But it wasn’t until the mid-1950s that a plan for what would one day be called the “Dwight D. Eisenhower National System of Interstate and Defense Highways” was drafted. 

A 1957 map shows the plan for the Interstate Highway System as the original system was just beginning to be built. Like the 1947 map above, it is very similar to the 1922 Pershing Map. (Map: Federal Highway Administration)

Federal Highway Act and the birth of the Interstate Highway System

President Eisenhower signed the Federal Highway Act of 1956 into law, which authorized 41,000 miles of interstate highways. The first mile was constructed the same year; it was estimated that the entire Interstate Highway System (IHS) would be completed by 1976. 

However, the IHS was not considered finished until 1991 (and improvements, new interstate highways, etc. continue to this day). In addition, the interstate highway system undergoes constant analysis in the best interest of defense, commerce and public use. While the system is a vital public resource, it remains a focus of the Department of Defense’s Strategic Highway Network. That network is a 140,000-mile web of government-designated highways and roads connecting military installations, economic hubs, railroads and ports.

President Eisenhower signs the Federal Highway Act of 1956, authorizing the construction of the Interstate Highway System.
(Photo: Federal Highway Administration)

What is often termed the greatest public works project in American history is overseen by the U.S. Department of Transportation’s Federal Highway Administration, partnering with local and state transportation agencies. Although the maintenance and expansion of the IHS are civilian responsibilities, the Army remains a crucial player in the mix. Its Transportation Engineering Agency (TEA), a division of the Army’s Military Surface Deployment and Distribution Command, continually assesses the interstate highways to determine if they meet the needs of the Department of Defense. TEA also coordinates with public agencies to establish policy regarding military use of public roads.