Conversation so far:
Where was David McCullough born?
David McCullough was born in the Point Breeze neighborhood of Pittsburgh, Pennsylvania, the son of Ruth and Christian Hax McCullough.
What did David McCullough's parents try next after his birth to educate him
David McCullough's parents and his grandmother, who read to him often, introduced him to books at an early age
What did David McCullough's parents say to him in discussions to stimulate his burgeoning young mind
David McCullough's parents often talked about history, a topic he says should be discussed more often.

Question: What was his next work
Self-contained rewrite: What was David McCullough's next work after becoming a young man