How did shiloh end the thought that the war was going to be a quick one?

It put an end to the idea that one Rebel was worth ten Yankees.

Neither side backed down despite the terrible losses.

i got it right on test

Explanation:

the  wilmot proviso  was designed to eliminate  slavery  within the  landacquired as a result of the mexican war (1846-48). fearing the addition of a pro-slave territory, pennsylvania congressman david  wilmot proposedhis amendment to the bill.