The origin of the United States' Interstate Highway system goes back to the 1930s.

The Federal-Aid Highway Act of 1938 stated:

The Chief of the Bureau of Public Roads is hereby directed to investigate and make a report of his findings and recommend to the Congress not later than February 1, 1939, with respect to the feasibility of funding, and cost of, superhighways not exceeding three in number, running in a general direction from the eastern to the western portion of the United States, and not exceeding three in number, running in a general direction from the northern to the southern portion of the United States, including the feasibility of a toll system on such roads.

A report submitted to Congress in 1944 identified a super-highway network of almost 34,000 miles. The proposed routes clearly formed the basis for the current Interstate Highway system.

In Florida, the report proposed what are essentially today's I-95, I-4 and I-10. Mysteriously, the proposed route that presaged I-75 stopped just south of the Florida-Georgia border and did not continue farther south into the state.