Conversation so far:
Who was Robert Lincoln?
Robert Todd Lincoln was an American politician, lawyer, and businessman and the first son of President Abraham Lincoln and Mary Todd Lincoln
How was Robert Lincoln rescued?
Edwin Booth saved Abraham Lincoln's son, Robert, from serious injury or even death. The incident occurred on a train platform in Jersey City, New Jersey.

Question: How did this all come to light?
Self-contained rewrite: How did Edwin Booth's rescue of Robert Lincoln all come to light?