America's historic lands are disappearing - and the rate of loss will continue accelerating without quick action, historians and federal officials say.

More than 100 "nationally significant" battlefields and historic sites from the American Revolution and War of 1812 are already gone, a survey by the National Park Service has found. An additional 245 are in poor condition or fragmented, and 222 are in danger of destruction in the next 10 years.

While Civil War sites have tended to receive protection, many from the earlier wars are at risk. Some are nearby, including the sites of George Washington's crossing of the Delaware River on Christmas night in 1776; the first Battle of Trenton on Dec. 26 of the same year; the second Battle of Trenton on Jan. 2, 1777; the Battle of Princeton the following day; and the Battle of Brandywine in September 1777, according to the Pulitzer Prize-winning historian and author David Hackett Fischer.

"These endangered sites are located on open land in suburban or exurban areas around our cities and large towns," Fischer said in congressional testimony in January. "As urban growth begins to revive after the great recession, real estate development is picking up again, and the loss of historic sites will increase with it, unless we find a way to deal with it."

Dealing with the problem is the aim of legislation, which passed the U.S. House Committee on Natural Resources last week and is now going to the full House for a vote. The measure would provide federal matching grants to preserve battlefields from the Revolutionary War and the War of 1812, along with the Civil War.

"Each time a historic battlefield is replaced with a parking lot, a chapter of American history is obscured, and future generations lose an important window onto their heritage," said the bill's author, U.S. Rep. Rush Holt, a Democrat from central New Jersey. "This bill would provide matching funds that would leverage private efforts to preserve our nation's past."

The legislation would build on the success of the American Battlefield Protection Program (ABPP), which provides matching grants in support of private efforts to preserve Civil War sites. Since 1999, the National Park Service program has helped to save more than 16,500 acres of historic sites in 14 states.

Holt's bill would reauthorize the ABPP and create a similar program to work with state and local governments and nonprofit groups to preserve battlefields from the Revolutionary War and War of 1812. He had introduced similar legislation in the last session of Congress, and it passed the House unanimously.

The new measure is supported by historic preservation organizations, including the National Trust for Historic Preservation, the Civil War Trust, the Crossroads of the American Revolution Association, and the National Parks Conservation Association.

A Senate version of the bill, proposed by New York Sen. Charles Schumer, is awaiting action.

"The public-private partnerships fostered through the American Battlefield Protection Program have been responsible for setting aside some of our nation's most significant historic sites," said James Lighthizer, president of the Civil War Trust. "But our nation was not only shaped on the battlefields of the 1860s - and this measure will help encourage the protection and appreciation of the full scope of our history."

In Trenton, where fighting during the Revolution took place along a street grid that still exists, Holt's measure finds strong support.

"It's important to preserve [historic] land where you can because when it's gone, it's gone," said Richard Patterson, executive director of the Old Barracks Museum, the Trenton quarters once used by British, Hessian, and American troops. "Most people, sitting in their living room, will say, 'What difference does it make?'

"But when they go there, they are overcome by the immediacy of the whole thing," he said. "Americans are not just interested in preserving the image of something. They value the original, the land where these things happened."

Donations have been generally lacking, especially because of the economic downturn, Patterson said. "There's been no incentive for quite a while," he added. "There's no money anywhere, so when something like this [bill] comes along, it's a godsend.

"It's exactly the way the public and private sectors should work together."

Among the sites covered by the legislation are hundreds of battlefields and associated sites across New Jersey and Pennsylvania.

The loss of some land is "the inevitable price we pay for economic growth, which is fundamental to the health of this great republic," said Fischer, who won a 2005 Pulitzer Prize for his book Washington's Crossing. "But even as development continues, we could protect some of the most important sites, and this legislation would make a major difference that way."