His department was awarded the Collier Trophy of 1928 for its contribution to the "development of airways and air navigation facilities".

MacCracken then returned to his private law practice, where he continued to be involved in the growth of commercial aviation by representing many major airlines.

For that reason Postmaster General Walter F. Brown asked him to preside over what was later described as the Spoils Conference, to work out an agreement between the carriers and the Post office to consolidate air mail routes into transcontinental networks operated by the best-equipped and financially stable companies.

[4]: 430 While Brittin promptly served his sentence, MacCracken continued to resist the Senate’s authority, filing a petition of habeas corpus in federal courts to overturn his arrest.

After litigation, the U.S. Supreme Court unanimously ruled that Congress had acted constitutionally, denied the petition in the case Jurney v. MacCracken,[5] and forced him to serve his sentence.