Now don't get me wrong. There's no easy way to find out if one of your ancestors invested in the Dutch Tulip Bubble of 1637, or how much your family lost in the Great Panic of 1893. But there are ways to search millions of more recent records from business and finance, with the possibility of finding out something about one of your ancestors or relatives.
Here are the best sources I know of:
EDGAR. The Electronic Data Gathering, Analysis, and Retrieval system at the SEC is a huge (and I don't use that word loosely) source of information on companies, and the people in them, especially executives and major investors. The EDGAR Full Text Search covers just the past four years of business reports, but includes the names of millions of people from both US and foreign companies. You can retrieve company reports going back to the 1990's, but there's no easy way at EDGAR to search through text older than four years.
Famous rich guy, J.P. Morgan, and no, that's not a knife he's holding.
NARA Business and Financial Archives. There are some big honkin' business databases at the National Archives as well, but not all of them contain names of individuals. Take a look in particular at:
- Records of Prime Contracts Awarded by the Military (8 million records, 1975-2003)
- Records on Trading of Securities by Corporate Insiders (5.5 million records, 1978-2001)
- Records of Contracts Awarded by Federal Agencies (8 million records, 1978-1997)
Jigsaw. The service at jigsaw.com is the best business contacts database I know of, with more than 16 million records. Since these are up-to-date records, you won't find anything on ancestors here, but you certainly might find distant, still-living family members. A name search is free, and returns useful information. For instance, a search on Jason Bourne turns up a listing at the CIA (for real!). But to get a full listing, you'll have to subscribe to the Jigsaw service.
MissingMoney. For a wide variety of reasons (including passing on), people sometimes leave behind unclaimed assets -- bank accounts, insurance policies, pensions, and so on. Your relatives might be on the list here. Enter their name in the search box, and enter ZZ for the state to conduct a national search. (And as long as you're here, search on your own name as well...something might turn up!).
Visit the main page of Free Genealogy Tools for more, umm, free genealogical tools.
And don't forget to also check for your family history at Ancestry.com and NewspaperArchive.com. These are subscription databases, but they are among the most powerful research tools available for looking into family roots.