The Federal-Aid Highway Act of 1956 was a significant piece of legislation in the United States that established the framework for the construction of the Interstate Highway System. This act allocated $25 billion over 12 years to build approximately 41,000 miles of highways, aimed at improving national defense and facilitating interstate commerce. The act was signed into law by President Dwight D. Eisenhower, who recognized the need for a modern highway system. It also introduced a federal-state partnership, where the federal government would cover 90% of the construction costs, while states would manage the projects and maintenance.