Don't Forget State and Local Sources

All United States companies -- public or private -- are required to file with the Secretary of State in the state where the business was incorporated, and sometimes with municipal authorities as well. These filings are not nearly so detailed, especially in terms of finances, as federal SEC filings, but can still reveal some good information, including articles of incorporation and names and contact information for company officers. Check the company web site for incorporation information. Once you know where the business is incorporated, check that Secretary of State's web site to see how you can access the information.