The exhibition centers on 200 years of American history as seen from the doorstep of one house that stood from colonial days through the mid-1960s in Ipswich, Mass. The Georgian-style, 2¹/2-story timber-framed house was built in the 1760s just 30 miles north of Boston and stood at 16 Elm St. until 1963, when efforts by Ipswich citizens saved it from the bulldozer.

As the largest single artifact in the Smithsonian's National Museum of American History, this 4,200-square-foot house features information about five families whose lives within the walls of the house became part of the great changes and events of the nation's history. Inside this house lived nearly 100 occupants who have made history come alive for the more than 6 million annual visitors to Smithsonian's National Museum of American History. Visitors can peer through its walls, windows and doors to view settings played out against the backdrop of colonial America, the American Revolution, the abolitionist movement, the industrial era and World War II.

The exhibition tells stories about how some American families made history in their kitchens and parlors. Inside this house, American colonists created a new genteel lifestyle, patriots set out to fight a Revolution, and an African American struggled for freedom. Neighbors came together to end slavery, immigrants made a new home and earned a livelihood, and a woman and her grandson served on the homefront during World War II.

Visitors to the exhibit are encouraged to look at their own homes to find clues within the walls to help determine who lived in a house and what the neighborhood was like and to figure out when a house was built.

Public records, private reflections and photographs can all help reconstruct the history of a house. From wills and deeds on file in town or county records, a researcher can find a list of owners, while census records, city directories, photographs, maps, diaries and interviews with former residents all add pieces to the puzzle.

Looking at the style of the home is also a way to help figure out when it was built. Most housing forms and styles were popular in a particular place and time. If the construction date of a house is not known, stylistic characteristics, construction dates and techniques for houses in a region can help identify the time frame. Tiny structural details can also tell part of the story. Nail holes, paint and paint shadows, bits of wallpaper and tool marks on boards are some of the clues to look for to see whether previous residents added or removed walls or windows as they adapted the space to suit their own needs and tastes.

For more information about the "Within These Walls" exhibit, sponsored by the National Association of Realtors, visit www.americanhistory.si.edu/house.

Information provided in this column is presented by the Realtor members of the Silicon Valley Association of Realtors at www.silvar.org. Send questions on any topic to jnewton@jnpr.com.