The Significance of the Interstate Highway Act of 1956

Significance Interstate Highway Act 1956

One of the biggest construction projects with the most historical significance was the United States’ Interstate Highway Act of 1956. The bill played a monumental role in shaping the future of the US and transforming the national landscape.

The Interstate Highway System had its origins in the woes of the Great Depression. World War II interrupted these plans, though Congress quickly revisited it during the post-war economic boom.

President Dwight D. Eisenhower championed the bill and believed that the construction of a national interconnected Interstate Highway System would be integral to the economic development and defense of the nation.

Though devising the uniform standards and financing for such a large project would prove difficult, Congress finally passed the Federal Aid Highway Act of 1956. Historians widely refer to the bill as the National Interstate and Defense Highways Act.

Congress would go on to authorize $25 billion in funding over a twelve year period for the project. The project initially only included ~41,000 miles of highways, though the total mileage has grown since then.

The completion of the Interstate Highway System ushered in a new age that fundamentally altered the transportation preferences of Americans. It began a new age of the automobile.

It also spurred social developments including the suburbanization of America as city dwellers moved to nearby suburbs where land was cheaper.

Though the Interstate Highway System brought many positive developments to the United States, its legacy is also tainted by the destruction it wrought on communities.

Black and other disenfranchised communities were primarily impacted when highway construction leveled homes and displaced thousands. Some communities have never recovered.

The History of the Interstate Highway System

The History of the Interstate Highway System of the United States dates back to the early 20th century. The popularity of the Ford Model T pressured states to build new and better roads to accommodate the emerging demand for automobiles.

However, efforts at road building were highly localized and largely state-operated and funded. There was very little federal coordination or funding for highways in these early years.

During the Great Depression President Franklin D. Roosevelt favored the construction of an Interstate Highway System as a way to provide jobs for more people.1

The resulting Federal Aid Highway Act of 1938 commissioned the Bureau of Public Roads (BPR) to study the feasibility of a proposed network of toll roads crisscrossing the nation.

1919 Transcontinental motor convoy
The 1919 Transcontinental motor convoy revealed the decrepit state of America’s transportation system via Wikimedia

The study would ultimately recommend that the construction of an Interstate Highway System would be beneficial to the interests of the nation. The outbreak of World War II halted any serious efforts at building an integrated system, though only for a brief period.

As the tide began to turn in the Allies’ favor, Roosevelt began planning for post-war America. There were fears in the early 1940s that the Great Depression would resume after the war was over and millions of soldiers returning from overseas would not have jobs to go back to.

Congress passed the Federal Aid Highway Act of 1944 to help allay those fears. The act provided additional funding for highway improvements, though otherwise maintained status quo.

Importantly, the act also authorized the construction of over 40,000 miles of a “National System of Interstate Highways.” Despite this bold declaration, special funding was not provided, nor was there a defined agreement between how much funds would come from states versus the federal government.

Over the next decade the lack of a defined agreement and vision would lead to the completion of only ~6,500 miles.

The Interstate Highway Act of 1956

When Dwight D. Eisenhower became president in 1953, he immediately prioritized fully funding the construction of a National Interstate Highway System.

Eisenhower had personal experience with the decrepit state of the American highway system. In 1919 he joined the US Army’s first transcontinental motor convoy that traveled from Washington, DC to San Francisco.

The convoy traveled along Lincoln Highway and took nearly two months to complete. Over three decades later that state of America’s highways had only minutely improved. America needed a better system to link the coasts through the American mainland.

The Eisenhower administration proposed a highway system that required financing through a federal bond issuance and where states provided nearly 70% of the costs. This plan was based on the recommendations of the Clay Committee.

Both the Senate and House summarily rejected Eisenhower’s plan. Both would go on to propose their own versions.

Eisenhower Interstate Highway Act
President Eisenhower with Interstate Highway System sign via Wikimedia

Senator Albert Gore, Sr. sponsored the Senate’s version. Gore’s bill flipped the cost-sharing proposal, arguing that the federal share should be 75%. The Senate approved Gore’s proposal, though it notably left the financing mechanism up to the House of Representatives’ proposal.

The House bill would eventually be a combination of efforts from Hale Boggs and George Fallon. The proposal included the creation of a Highway Trust Fund that would be funded through an increased gas tax and taxes on vehicle parts that utilized the system.

In this version, the federal government would assume 90% of the costs. Eisenhower was no fan of the “pay as you go” approach, though eventually compromised.

Eisenhower signed the resulting Interstate Federal Aid Highway Act of 1956 into law on June 29, 1956. For such a monumental bill that would change the landscape of the United States, it received relatively little fanfare.

Eisenhower signed from the Walter Reed Medical Center as he was recovering from an intestinal ailment.

The Interstate Highway Act and the Cold War

The Interstate Highway Act had a profound impact on the Cold War landscape of America by helping to bolster the United States’ national defense system and turbocharging the economy by ridding it of gross inefficiencies.

One of Eisenhower’s primary reasons for focusing on the construction of an Interstate Highway System was for national defense. The German autobahn network impressed Eisenhower during World War II as he recalled distinctly how much faster Allied troops moved upon entering German territory.

Should the US become engaged in a land war on American soil, the existing transportation networks to move troops and supplies were woefully inadequate. The threat of nuclear war during the Cold War also highlighted that the Interstate Highway Act could help create new roadways to evacuate cities in an orderly manner should the need arise.2

In order to keep up with its Cold War foes the United States also needed to leave behind the inefficiencies bogging down its economy.

The Interstate Highway Act of 1956 chart

At a 1954 conference with state governors Vice President Richard Nixon stepped in for Eisenhower to deliver a speech on why the United States needed the national Interstate Highway System.

Nixon cited the inefficiencies of the current highways that led to losses of billions of dollars in traffic jams and the clogging of the nation’s courts with highway-related lawsuits.

In addition, the existing highways led to an ineffective transport of goods, hampering the economy, and an unacceptably high death and injury toll from automobiles.

All of these factors were limiting the American economy and the nation’s growth. Should the United States wish to keep up with the Soviet Union in the Cold War, such gross inefficiencies needed improvements.

With the subsequent passage of the Federal Aid Highway Act in 1956, President Eisenhower hoped to address these issues. He could not have known the other monumental societal changes that would occur as a result of the program.

The Significance of the Interstate Highway Act

The historical significance of the Interstate Highway Act lies in how it completely transformed the societal landscape of America interlinking cities and opening up more of America for development. The act also notably negatively affected communities of color as administrators planned the new highway locations to separate or destroy poor, disadvantaged communities.

Transforming America

The Interstate Highway Act held great significance in the way it transformed America. As the Interstate Highway System was built throughout the 1950s-1970s, America’s largest cities were finally all interconnected.

Citizens could now more easily travel longer distances between cities and arrive faster. Tourism skyrocketed as motels, towns, and cities sprung along the new highways. Americans could now easily explore more of the country.

The act fundamentally transformed the shipping of products and goods as well. New interstates provided cheaper shipping costs and the use of truck transport increased dramatically.

Interstate Highway System 1956 map
Map of Interstate Highway System in 1958 via LOC

The Interstate Highway System also further led to the suburbanization of America. Primarily upper and middle class families led a mass exodus from the cities to the suburbs where land was cheaper and more accessible. The new highways allowed them to commute back into the cities where many jobs were located.3

The new interstates also opened up more of America for further development and settlement. A “sunbelt shift” occurred, during which the populations of the American South and West exploded, while the gains in the high density populations of the Midwest and East were more subdued.

While the highways no doubt played a large role, the development of the West in particular was also aided by large public works projects such as the Hoover Dam that delivered water more efficiently to population centers.

Interstate Highway System and Racism

The building of the highway system did not come without its downsides. The policy effectively cut off entire towns and communities from society as the prior roads that brought in travelers fell out of use in favor of the new interstates.

In addition, in order to receive the vast federal funds, municipalities needed to connect new roads directly through their cities. Lawmakers often chose the locations of these new highways at the expense of disenfranchised communities.

These communities were predominantly composed of people of color, who were forced to relocate to other areas as the highways destroyed their homes, churches, and businesses. In some cases, overt racism was the driving factor behind where these highways would be built.

The winding I-20 through downtown Atlanta makes little sense, until one realizes that the path blazed through areas of historically black communities. In St. Paul, Minnesota the highway construction displaced nearly one-seventh of the black community.

i20 construction Atlanta
Construction of i20 in Atlanta via AJC

The community of Overtown in Miami, Florida was a thriving black community and once considered the “Harlem of the South.” Coincidentally, it was wiped off the map when I-95 was built displacing over 10,000 people in the process.4

When highways did not directly destroy minority neighborhoods, the new highways were often built right between black and white communities, serving as a physical racial barrier. 

Inversely, wealthy neighborhoods in Washington DC and New York City were successfully able to block and cancel planned highway constructions through their neighborhoods. The influence and power held by the well off left disenfranchised communities to bear the worst of the new highway system.

Though there were many positive effects and developments of the Interstate Highway System, it did not come without its downsides.


To learn more about US history, check out this timeline of the history of the United States.


1) Blas, Elisheva. “The Dwight D. Eisenhower National System of Interstate and Defense Highways: The Road to Success?” The History Teacher, vol. 44, no. 1, 2010, pp. 127–42. JSTOR,

2) CURTISS, C. D. “The National System of Interstate Highways.” The Military Engineer, vol. 47, no. 318, 1955, pp. 274–77. JSTOR,

3) Brinkman, Jeffrey, and Jeffrey Lin. “Early Interstate Policy and Its Effects on Central Cities.” Cityscape, vol. 22, no. 2, 2020, pp. 81–86. JSTOR,

4) Connolly, N. D. B. “Colored, Caribbean, and Condemned: Miami’s Overtown District and the Cultural Expense of Progress, 1940-1970.” Caribbean Studies, vol. 34, no. 1, 2006, pp. 3–60. JSTOR,

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