This is a retouched picture, which means that it has been digitally altered from its original version. Modifications: cropped to show Michigan only. The original can be viewed here: Interstate Highway plan June 27, 1958.jpg: . Modifications made by Paddu.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.