Conversation so far:
When did Thomas A. Hendricks become Senator?
Thomas A. Hendricks represented Indiana in the U.S. Senate from 1863–1869.
What did Thomas A. Hendricks do as senator?
Thomas A. Hendricks challenged what he thought was radical legislation, including the military draft and issuing greenbacks.
What did Thomas A. Hendricks stand for?
Thomas A. Hendricks supported the Union and prosecution of the war, consistently voting in favor of wartime appropriations.

Question: What did he oppose?
Self-contained rewrite: What did Thomas A. Hendricks oppose?