Search for unclaimed assets.

Unclaimed property offices in all 50 states are the most common hiding places for unclaimed assets. The National Association of Unclaimed Property Administrators is an excellent starting point. It lists state offices and provides directions for filing claims.
The Pension Benefits Guarantee Corporation site features a directory of 2,700 people owed a total of $10 million from terminated pension plans.
The U.S. Department of Veteran Affairs is the repository of thousands of
disability accounts and benefit packages returning military personnel didn't
bother to collect. Folks with relatives who served in conflicts dating back
to the Civil War could be the heirs.