Betty G. Y. Shields, Susan C. Holton, and Harton S. Semple Jr., staff of the Sewickley Valley Historical Society, have drawn on their command of and enthusiasm for local history to...voir plusBetty G. Y. Shields, Susan C. Holton, and Harton S. Semple Jr., staff of the Sewickley Valley Historical Society, have drawn on their command of and enthusiasm for local history to produce this survey.voir moins