All American non-profits and charities are required to annually submit financial statments on the IRS Form 990. Non-profits are required to allow the public to inspect these records during regular business hours. Many organizations will post these forms on their website.
You can frequently search for the name of the organization and Form 990 and find the form. Or you might try searching for the name of the organization and "annual report."
Also, written requests to the IRS can be directed to:
Commissioner of Internal Revenue
Attn: Freedom of Information Reading Room
1111 Constitution Avenue, NW
Washington, DC 20224