Our ancestors left countless clues to their pasts, but we don't always find them in the obvious places. While official documents get filed in courthouses or archives, more-personal memorabilia, such as family Bibles, postcards, letters and photograph albums, get relegated to attics, basements or bottom drawers. Over time, these items may get lost, discarded or sold. For example, when my father bought a 150-year-old estate home (a house left by a deceased person) in New Orleans, he found an attic full of letters and documents from generations past. Apparently, inheritors eager to sell off the deceased's old home had abandoned these genealogical treasures.

Everyday items such as these are often discarded as junk or overlooked by people uninterested in their family's past. But the growing interest in both genealogy and local history has generated a booming business dealing in heirlooms and genealogical information. In fact, pieces of your own family history probably are for sale—but where? Try these six sources to find those long-lost heirlooms and buy them back.

Those old antiques
When most people think of antiques shops, they think of furniture and other household items that aren't easily traceable to their former owners. But search the corners of an antiques shop, and you'll usually find items that are much more personal and, to genealogists, much more valuable. Some antiques shops deal exclusively in documents, letters, photographs and other paper products. For instance, at a shop in Seattle, I found early 20th-century playbills containing actors' names and local ads from New York City and Boston; they cost $15 to $25 each. The same shop had bins of postcards depicting early 20th-century life for $1 to $2 each. Prices for genealogical materials in antiques shops vary widely. An 1891 photograph of three children cost $6.50, while a 1942 picture of the Seattle Fire Company cost $85. A letter between two prominent Civil War generals can cost more than $1,000, while postcards from the late 1800s cost as little as 50 cents.