Conversation so far:
What was Thomas Nast's career like?
German-born American caricaturist and editorial cartoonist Thomas Nast, the Father of the American Cartoon, was associated with Harper's Weekly from 1859 to 1860 and from 1862 until 1886.
What did Thomas Nast do in England?
In February 1860, Thomas Nast went to England for the New York Illustrated News to depict the prize fight between the American John C. Heenan and the English Thomas Sayers
What sporting event was Thomas Nast depicting in England in 1860?
In February 1860, Thomas Nast went to England for the New York Illustrated News to depict the prize fight between the American John C. Heenan and the English Thomas Sayers
What did Thomas Nast do for the prize fight between the American John C. Heenan and the English Thomas Sayers?
Thomas Nast depict the prize fight between the American John C. Heenan and the English Thomas Sayers
What else is notable about Thomas Nast's career besides depicting the fight between the American John C. Heenan and the English Thomas Sayers?
After the American Civil War, Nast strongly opposed the Reconstruction policy of President Andrew Johnson

Question: What did he do to oppose the policy?
Self-contained rewrite: What did Thomas Nast do to oppose the Reconstruction policy of President Andrew Johnson?