Conversation so far:
what happened in 2011 to Lin-Manuel Miranda?
In 2011 Lin-Manuel Miranda co-wrote the music and lyrics for Bring It On: The Musical with Tom Kitt and Amanda Green.
what happened in 2014 to Lin-Manuel Miranda?
In 2014 Lin-Manuel Miranda also wrote music and lyrics for the one-act musical 21 Chump Street
where did Lin-Manuel Miranda perform in 2014 after he wrote music and lyrics for the one-act musical 21 Chump Street?
Lin-Manuel Miranda performed as narrator for the show's single performance at the Brooklyn Academy of Music on June 7, 2014, which was broadcast on NPR's This American Life.

Question: what was his greatest accomplishment?
Self-contained rewrite: what was Lin-Manuel Miranda's greatest accomplishment?