In 1945, Arnold directed the founding of Project RAND (which became the RAND Corporation, a non-profit think tank) with $10,000,000 of funding left over from World War II.
Leta 1941 je prejel častni doktorat Vojaškega kolidža Pensilvanije "(Pennsylvania Military College)" in Univerze južne Kalifornije "(University of Southern California)" in leta 1942 še od Kolidža Iowa Wesleyan "(Iowa Wesleyan College)".