During these years , he narrowed his focus to an intended three - volume history of Mormonism , but maintained his interest in the American fur trade and exploration .
Of necessity Morgan acted as an independent historian between 1947 and 1952 .
During these years , Morgan narrowed Morgan 's focus to an intended three - volume history of Mormonism , but maintained his interest in the American fur trade and exploration .
Of necessity Morgan acted as an independent historian between 1947 and 1952 .