Construction on the Iowa Turnpike would never begin. In January 1956, the Federal-Aid Highway Act of 1956 (H.R. 8836) was introduced in Congress. H.R. 8836 created the Interstate Highway System, a national system of controlled-access highways. President Dwight D. Eisenhower signed the bill into law on June 29, 1956. The new law was problematic for the Iowa Turnpike for a couple of reasons. Firstly, the law designated of controlled-access highway in Iowa, including a cross-state route in the vicinity of the turnpike's planned route. Secondly, the federal government was going to pay for ninety percent of the construction costs; states were only required to match ten percent of costs (however, tolls were generally prohibited). The Interstate Highway System's completeness and financing rendered the Iowa Turnpike obsolete before it was ever constructed.