Howard remained active in Republican Party politics, serving as an elector in the 1872 presidential election which granted a second term to Ulysses S. Grant. In 1873, Howard was elected to the first of two consecutive terms as Governor of Rhode Island. He declined to seek a third term. In 1876, he served once again a delegate to the National Republican Convention, and in 1878 he was nominated by President Rutherford B. Hayes as an assistant commissioner to the Paris Exposition.