Has more than 1/3 of Congress ever opposed a war?

Question

Basically all the bills to start a war had 90-99% congressional support from what I've seen on Wikipedia. I just wonder if there was any war that 30% or more of Congress opposed starting. I am only asking about the start of the war not its continuation. Wars always have overwhelming support but then winds down. Also exclude cases like Vietnam where there was no congress at all.

Answer 1

Look up the Senate vote in the Spanish-American War of 1898. Looks like their vote feel short of ⅔ of the Senate.