The marriage ended in divorce in 1882. Before the divorce, Kate was accused of having an affair with the flamboyant and powerful New York Senator Roscoe Conkling. According to a well-known story, buttressed by contemporaneous press reports, Sprague confronted the philandering couple at Sprague's Rhode Island summer home and pursued Conkling with a shotgun and threatened to throw Kate out of a second story window. The shotgun incident with Conkling happened in 1879, but Kate was suspected of infidelities at least 10 years earlier. According to Salmon Chase biographer John Niven, "Whether second child...was Sprague's or had been conceived by another is a matter of speculation."