Conversation so far:
Why did Columbus Delano resign?
In 1875, Columbus Delano's reputation for personal honesty came under increasing scrutiny as revelations of corruption in the Grant administration continued to be the subject of investigations and media revelations.
Who was Columbus Delano?
Columbus Delano was a lawyer, rancher, banker, statesman and a member of the prominent Delano family.

Question: in what year did he resign?
Self-contained rewrite: In what year did Columbus Delano resign?