On Jan. 10, the Westmoreland County Historical Society will celebrate the 100th anniversary of its founding with a party that takes its theme from a day even more historic -- Gen. George Washington's wedding to Martha Custis in December 1759.

Scheduled from 6 to 9 p.m. at the Westmoreland County Courthouse in Greensburg, the party will feature food similar to that served at the Washingtons' wedding, as well as performance and dance instruction by the English Country Dancers.

Robert Hanna's Dark Horse Beer, brewed by the local Red Star Brewery to commemorate the founder of Hanna's Town, will make its debut at the event.

Founded in 1908, the Westmoreland County Historical Society, its 700,000-item archival collection and the 5,000-volume Calvin E. Pollins Memorial Library, for local history and genealogical research, are in the Stark Building in downtown Greensburg. Run by a 15-member board, the nonprofit society has a staff of six.

The society's executive director, Lisa Hays, said the intersection of the 250th anniversary of the Washingtons' wedding and the society's centennial points up the long and rich history of the area, and to the many ways the group manages the county's historical resources.

"Most people associate Westmoreland County with its history as a coal and coke mining region," she said. "But this was the proving ground for the young Washington, and a central front during the Revolutionary War."

Along with Westmoreland County Parks and Recreation, the Society maintains Historic Hanna's Town in Hempfield, a partial reconstruction of the first county seat of Westmoreland, which was founded in 1775. Much of Hanna's Town was burned to the ground in 1782 by Native Americans allied with the British in one of the final battles of the Revolutionary War.

Ms. Hays noted the destruction of Hanna's Town and the 1786 decision to move the county seat to its present home, Greensburg, resulted in one of the historical society's greatest treasures -- the archaeological collection excavated from the site, which numbers more than a million pieces.

"After everyone left, the area became farmland, leaving everything below a couple of feet undisturbed," said Ms. Hays. "It's a unique snapshot of how people in Westmoreland County were living in the late 1700s."

She added that tools and pieces of pottery from the collection, some imported from overseas, show the important role that Westmoreland County played in the settling of land west of the Allegheny Mountains.

The collection is housed at Westmoreland County Community College, but Ms. Hays said the Hanna's Town site has been only partially excavated, and the society has big plans for its future.

In 2007, the society began a capital campaign to raise $7.5 million for further exacavation and a history education center on the Hanna's Town site. The county has already pledged $1.1 million, and the groundbreaking was planned for this spring.

But as board chairman and Greensburg attorney P. Louis DeRose noted, the economic climate has forced the society to revise its plans.

"Corporations and other organizations have cut their giving to nonprofits like us," he said. "We've already seen that. That's why we need individuals to step in more than ever."

Volunteers are the lifeblood of the society, he added.

"We want you to become involved. You don't have to have money to help out."

Along with administering Hanna's Town and maintaining its archives, the society offers educational programs to schools and the public, publishes Westmoreland History Magazine and a quarterly newsletter, and coordinates the efforts of the smaller historical societies in the area.

Ms. Hays said that although times are hard, she believes preserving Westmoreland County history remains important to people's quality of life.

"There are people here all the time researching their family's history in our geneology library," she said. "People need food and health care, but they need history, too."

She added that there was a quotation by David McCullough, author of a noted biography of John Adams, that reminded her of history's importance.

"He said history inspires courage and tolerance, and that it is 'an aid to navigation in perilous times,' " Ms. Hays said. "I couldn't say it any better than that."