There seems to be some confusion about which award was authorized first, the United States Congresssional Medal of Honor or the authorization by the Confederacy for what would become the Roll of Honor. Was the Medal of Honor, a counter to the proposal for a Confederate medal, which became the Roll of Honor, or was it the other way around? The Confederacy also practised the English system of "being mentioned in official reports" as a method of honoring their hero's.
Appearently there was a move by both sides to honor valient service. Many of the earliest Medal of Honor such as for the Andrews Raid aka "the Great Locomotive Chase" were awarded for events that occurred well before the medal was established.