What did Americans know as the Holocaust unfolded? Quite a lot, it turns out

Growing up in Lowell, Massachusetts, in the 1950s and ’60s, Andrea Hoffman learned about the Holocaust at Hebrew school, and later married into a family that included Holocaust survivors. Along the way, certain questions haunted her.

”I’ve always wondered what people knew, when did they know it, how did they know it?” said Hoffman, 65. Her mother had…