The Civil War Preservation Trust has unveiled "History Under Siege(TM): A Guide to America's Most Endangered Civil War Battlefields," its annual report on the nation's most threatened Civil War sites.

"In town after town, the irreplaceable battlefields that define those communities are being marred forever," says CWPT President James Lighthizer. "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 was Academy Award-winning actor Richard Dreyfuss, who is also an avid student of history.

Of the need for historic preservation, Dreyfuss says, "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 ten 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 includes:

Cedar Creek, Virginia: An expanding limestone mine threatens the site of a major Union victory.

Fort Gaines, Alabama: Dredging practices have sped erosion at this fort defending Mobile Bay.

Gettysburg, Pennsylvania: High prices for historic land outside park boundaries have thwarted preservationists' efforts.

Monocacy, Maryland: A massive trash incinerator could go up at "the Battle that Saved Washington."

New Market Heights, Virginia: Preservationists have not yet been able to protect land at this key site in African American military history.

Port Gibson, Mississippi: Union troops deemed the town too beautiful to burn, but a proposed highway widening would cut through historic neighborhoods.

Sabine Pass, Texas: Repeated hurricane damage has shuttered the site of one of the war's most lopsided victories.

South Mountain, Maryland: A utility company is planning a natural gas compression station in the mountain pass.

Spring Hill, Tennessee: General Motors may sell 500 acres adjacent to the battlefield for high-density development.

Wilderness, Virginia: Wal-Mart plans a new 138,000-square foot store inside the battle's historic boundary.