The Society was organized on December 17, 1898, in Portland at the Portland Library Building. Its mission, as expressed in the first volume of its "Oregon Historical Quarterly", was to "bring together in the most complete measure possible the data for the history of the commonwealth, and to stimulate the widest and highest use of them." The first president was Harvey W. Scott, with memberships totaling 370 in the first year. George H. Himes was appointed the Society's first curator in 1899, a post he retained for four decades, until February 1939.