From the site, Mr. Lincoln's White House. Quotes are verbatim with my emphasis added:
* As Governor of Rhode Island (1861-63), he put himself in charge of state militia but refused a regular army commission unless he could be a major general.
* [H]e needed contacts [a wife] that could help keep his nine mills supplied with cotton and supply his need to feel important...
* Sprague's "Texas Adventure" involved a treasonous scheme to sell arms to Confederates in order to buy cotton; publicity about it was suppressed by Secretary of War Edwin Stanton.
* [As senator] Sprague defied his father-in-law [Chase] when he voted for Andrew Johnson's impeachment—a vote which was probably dictated by his vulnerability to legal reprisals from Stanton.
* Sprague financially supported his father-in-law's abortive search for the 1864 presidential nomination ...
You can take a creepy Internet tour of the Sprague mansion here.