Hook was nominated by President William McKinley on January 28, 1899, to a seat on the United States District Court for the District of Kansas vacated by Judge Cassius Gaius Foster. Hook's nomination was opposed by railroad companies, who were displeased that Hook had successfully won judgments against them while in private practice.[2] Nevertheless, he was confirmed by the United States Senate on January 31, 1899, and received his commission the same day. His service terminated on December 1, 1903, due to his elevation to the Eighth Circuit.[1]
On February 6, 1912, President William Howard Taft announced that he would nominate Hook to fill the vacancy on the United States Supreme Court that had been caused by the death of Justice John Marshall Harlan. Opposition was raised, however, by leaders of the NAACP, the Washington Bee, and other African-American newspapers and organizations. Concerned parties discussed Hook's decision in upholding the constitutionality of an Oklahoma Jim Crow law discriminating against African American passengers on trains crossing the state line between Kansas and Oklahoma.[3] The railroad interests also continued their opposition to Hook, as did large corporations displeased with his rulings in antitrust cases.[2] A prominent critic of the nomination was Governor of NebraskaChester Hardy Aldrich.[2]Mahlon Pitney was selected by the President in place of Hook.[4]
