In the Senate, Stevenson was a conservative stalwart, steadfastly opposing spending on internal improvements and maintaining a strict constructionist view of the constitution. He urged his fellow senators to oppose the Civil Rights Act of 1871, claiming that its provision that the president could suspend the right of "habeas corpus" in cases where he believed violence was imminent amounted to giving the chief executive the powers of a dictator. He also opposed the appropriation of federal money to fund the Centennial Exposition in Philadelphia, Pennsylvania, because he did not believe Congress was given the authority to make such an allocation under the Constitution.