 Mikesell served the U.S. government in a number of capacities, including serving as representative of the United States Treasury Department in Cairo in 1943-44 and as the U.S. delegate to the Middle East Financial Conference in Cairo (April, 1944); as a member of the United States Currency Mission to Saudi Arabia (1948); as member of the staff of the National Commission on Materials Policy; and Chief of the Foreign Resources Division (1951).He also served as an economic adviser to the Joint British-American Cabinet Committee on Palestine.He served as a consultant to the World Bank, the United Nations and the Organization of American States.