Overall good letter, but your kids may not have read past that.
from Answers.com among other sources:
Mr. Obama is 50% Caucasian from his mother’s side. He is 43.75% Arabic, and 6.25% African Negro from his father’s side, a great-great grandparent. His ancestors on his father’s side were Arab slave traders. They operated under an extended grant from Queen Victoria, who gave them the right to continue the slave trade in exchange for helping the British defeat the Madhi Army in southern Sudan and the Upper Nile region.