A hundred years ago, the situation on Mount Desert Island was quite different than it is here today. In 1901 a group of influential summer residents, under the inspiration and guidance of Charles W. Eliot, then Harvard's president, was worried that development of MDI would forever diminish its beauty. That year they formed the Hancock County Trustees of Public Reservations and chartered it in 1903 for legal status in Maine. They purchased land and sought land donations on MDI, which they later donated to the U.S. Government for federal preservation and protection. The Trustees honored some of the buyers and donors by remembering them or their loved ones in the form of memorials. They promoted these commemorative works as a way to encourage further land donations to the Trustees and U.S. Government. This spirit continued as the Park progressed through its development and expansion as Sieur de Monts National Monument (1916), Lafayette National Park (1919) and Acadia National Park (1929). Thus, Acadia NP came to be composed almost entirely of donated land.
The National Park Service, established in 1916 -- the same year as Sieur de Monts NM, seemed to encourage commemorative works as well. Shortly after its first director, Stephen Mather, had died in 1930, the NPS placed a bronze memorial plaque in his honor in just about every one of the national parks. In Acadia NP Mather's memorial is on the summit of Cadillac Mountain.*1
Times have changed. Ninety years after its establishment the NPS issued its Management Policies 2006.*2 On page 140, in section 9.6, titled Commemorative Works and Plaques, the document defines what a commemorative work is and states the rationale and justification for its establishment.