"In town after town, the irreplaceable battlefields that define those communities are being marred forever," CWPT President James Lighthizer said in a statement. "As we approach the Sesquicentennial of the bloodiest conflict in our nation's history, we need to be more aware than ever of the importance of preserving these sacred places for generations to come."
Joining Lighthizer at the event in Washington was Dreyfuss, an Academy Award-winning actor, who is also an avid student of history.
Of the need for historic preservation the film star said: "These hallowed battlegrounds should be national shrines, monuments to American valor, determination and courage. Once these irreplaceable treasures are gone, they're gone forever."
Dr. Libby O'Connell, chief historian for History, formerly The History Channel, also spoke at the event.
The report is composed of two parts: the 10 most endangered battlefields in the nation, followed by 15 additional "at risk" sites. Battlefields were chosen based on geographic location, military significance, and the immediacy of current threats.
The report mentions Cedar Creek, Va.; Fort Gaines, Ala.; Gettysburg, Pa.; Monocacy, Md.; New Market Heights, Va.; Port Gibson, Miss.; Sabine Pass, Texas; South Mountain, Md.; Spring Hill, Tenn., and Wilderness, Va.
Dreyfuss' film credits include "Jaws," "The Goodbye Girl," "Close Encounters of the Third Kind," "Mr. Holland's Opus" and "W."
Notable deaths of 2014 [PHOTOS]