List "plaque," followed by a comma. If the words you are citing are inscribed directly onto the memorial, you may want to list "inscription."
List the name of the memorial, followed by a comma.
List the name of the city where the memorial is located, followed by a comma.
List the state in which the memorial is located, followed by a comma.
List the date on which you gathered information at the memorial, followed by a period. List the day first, followed by the month and year. Your complete citation should be arranged in the following format:
Inscription, Joshua Chamberlain Memorial, Bangor, Maine, 11 July 2009.