The U.S. federal government first funded roadways through the Federal Aid Road Act of 1916, and began an effort to construct a national road grid with the passage of the Federal Aid Highway Act of 1921. After Dwight D. Eisenhower became president in 1953, his administration developed a proposal for an interstate highway system, eventually resulting in the passage of the Federal Aid Highway Act of 1956. Construction of the Interstate Highway System was proclaimed complete in 1992, though some planned routes were canceled and several routes have stretches that do not fully conform with federal standards. The cost of construction of the Interstate Highway System was approximately $114 billion (equivalent to $ in ). The original system has been expanded numerous times through the creation of new designations and the extension of existing designations.