在此列出,从维基上查到的,下面这段是简单的说明:
This list of the oldest companies in the United States includes brands and companies, excluding associations, educational, government or religious organizations. To be listed a brand or company name must remain, either whole or in part since inception, and should have been established before 1820. If the original name has since changed due to acquisitions or renaming, this must be verifiable.