In spite of his public silence, Grant was caught in the dispute between Congress and President Andrew Johnson. His position became intolerable after Johnson publicly accused Grant of dishonesty.

The same sense of duty that sent Grant to war in 1861 gave him no alternative to accepting the Republican nomination. "I could back down without, as it seems to me, leaving the contest for power for the next four years between mere trading politicians, the elevation of whom, no matter which party won, would lose to us, largely, the results of the costly war which we have gone through." From Washington, Grant monitored events in both the South and the West. He felt that military government could protect the citizenry when civil government faltered and endorsed the efforts of the congressional Indian Peace Commission.