scott was elected as a republican to the united states senate in 1869, and in 1870 convened a congressional inquiry into the atrocities of the ku klux klan, but was not a candidate for reelection in 1875. he served as chairman of the united states senate committee on claims during the forty-third congress. he moved to pittsburgh in 1875, and served as general counsel of the pennsylvania railroad from 1875 to 1877 and general solicitor from 1877 to 1895.