This is incredible. Are you saying the US Govt. took your family's genealogical records?? If I were you I would contact the President (certified mail, with copies to the National Archives, and whatever other agency might be involved). A letter to the press might also be in order.
It's possible those records may still exist somewhere. Do a Freedom of Information request (FOI). Just cite the Freedom of Information Act, but if you would be more comfortable having a lawyer do it for you I would not hesitate.