All foundations file a 990 PF form with the IRS. Page 10 or attachments list funded grants.
The Foundation Center provides a diagram of where to locate selected information on the Form 990 PF at http://fdncenter.org/funders/990pffly.pdf
GuideStar, a national database of nonprofit organizations, provides an excellent section on 990’s at http://www.guidestar.org/help/faq_990.jsp
Locate foundation 990 PF forms through these resources:
Foundation Center: 990 PF Search
Foundation Center: Foundation Finder
GuideStar: the National Database of Private Organizations