Conversation so far:
Where are the libraries?
public libraries throughout the United States, Britain, Canada and other English-speaking countries.
What led him to do this work?
he was inspired by meetings with philanthropist Enoch Pratt (1808-1896).
What happened with the libraries?
The Enoch Pratt Free Library (1886) impressed Carnegie deeply; he said, "Pratt was my guide and inspiration".

Question: When did his library open?
Self-contained rewrite: When did Andrew Carnegie's library open?