Who was United States Senator Edmund G. Ross of Kansas? I suppose you could call him a "Mr. Nobody." No law bears his name. Not a single list of Senate "greats" mentions his service. Yet when Ross entered the Senate in 1866, he was considered the man to watch. He seemed destined to surpass his colleagues, but he tossed it all away by one courageous act of conscience.

Let's set the stage.

Conflict was dividing our government in the wake of the Civil War. President Andrew Johnson was determined to follow Lincoln's policy of reconciliation toward the defeated South. Congress, however, wanted to rule the downtrodden Confederate states with an iron hand.

Congress decided to strike first. Shortly after Senator Ross was seated, the Senate introduced impeachment proceedings against the hated Pr…