Interracial Family Circle (Link can also be found on the Web Resources Page)From the home page -

Welcome to the official web site of the Interracial Family Circle (IFC), Washington, DC Metro Area Chapter. Located in the seat of the nation’s government, IFC members enjoy many of the beautiful buildings and vistas that abound the nation’s capital. Our members get together for fun events at local parks, museums, book readings, and more! Members also gain support and advice from each other by sharing their experiences as multicultural families. I hope that you will join us for many of these activities, from hosting “Circle Chats” to leading book club discussions and writing articles for the newsletter. Leave your comments below to get involved.

“An international association organizations dedicated to advocacy, education and collaboration on behalf the multiethnic, multiracial and transracial adoption community.”

AMEA is a wonderful national organization that works to educate people about the issues that affect the mixed heritage/ethnicity population. They are well know for their activism in the areas of mixed heritage eductional issues, health issues and policy issues pertaining to the collection of useful and appropriate demographic data by the federal government.
While I have not personally had experience working with this group, I do know that they commonly work with many other national organizations such as MAVIN as well as with other organizations on a more local level.
AMEA (this link opens a new page) This link can also be found on the Web Resources Page.