Conversation so far:
what happened to Andrew Carnegie in 1901?
public attention was turned from the shrewd business acumen to the public-spirited way in which Andrew Carnegie devoted himself to utilizing it on philanthropic projects.
were andrew carnegie's philantropic projects a success?
the establishment of public libraries was among Andrew Carnegie's many sucessful philanthropic efforts.
what did Andrew Carnegie do as a business magnate?
Andrew Carnegie built Pittsburgh's Carnegie Steel Company

Question: what was his greatest accomplishment?
Self-contained rewrite: what was Andrew Carnegie's greatest accomplishment?