[3] He attended the common schools and graduated from the University of Wisconsin with a Bachelor of Philosophy (Philosophiae Baccalaureus, or P.B.)

[4][a] While in college, Spooner joined the Psi Upsilon fraternity[5] and was admitted to membership in Phi Beta Kappa.

[6] During the Civil War, he enlisted in the Union Army as a private assigned to Company D, 40th Wisconsin Infantry, a three-month unit.

[7] After the war, Spooner served as private secretary to Wisconsin Governor Lucius Fairchild,[8] and then the governor's military secretary with the rank of colonel[9] He later served as quartermaster general of the Wisconsin Militia with the rank of brigadier general.

[3] He was elected as a Republican to the United States Senate January 27, 1885,[8] and served from 1885 to 1891, being defeated for re-election by William F.

[13] As a Senator, Spooner was credited with the Sherman Antitrust Act of 1890 provision that enabled the government to prosecute Standard Oil.

[13] Spooner and fellow Wisconsin Senator, Robert M. La Follette, were known to be bitter rivals.

[17] Spooner's view of political campaigns if direct primaries became standard was: Direct primaries would destroy the party machinery ... and would build up a lot of personal machines, and would make every man a self-seeker, and would degrade politics by turning candidacies into bitter personal wrangles.

[18]Spooner shocked the state of Wisconsin and much of the American political world with his sudden resignation in March 1907.

In his letter to the Governor, he explained that he felt the need to return to the legal profession in order to build a financial cushion to provide for his retirement and his heirs.

[19] Members of the political media also speculated that Spooner had timed his resignation to catch the La Follette faction off guard and unprepared for a Senate campaign.