The Setauket Presbyterian Church and Burial Ground is the site of the 1777 Battle of Setauket occuring between Loyalists and a force of Continentals from Connecticut. The current church was built in 1812, but the burial ground dates back to 1660's.
Historical, National Register of Historic Places (NRHP)
The battle is portrayed in the Season 1 finale of AMC's "Turn: Washington's Spies."
Links: www.setauketpresbyterian.org, en.wikipedia.org