As archbishop, Hanna was often tasked with helping resolve labor disputes. In 1921, he was named chairman of San Francisco's Wage Arbitration Boards; Hanna served on the boards through 1924. Governor James Rolph appointed Hanna as the chairman of a state mediation board to resolve the 1933 cotton strike in Corcoran, California. During the 1934 West Coast waterfront strike, President Franklin Roosevelt named Archbishop Hanna chairman of the National Longshoremen's Board. The board was tasked with resolving the strike by mediating between the International Longshoremen's Association, the International Seamen’s Union, and their employers.