Were sabres used effectively in U.S. Civil War?

[sirupate]

I don't know how effectively they were used in a technical sense, but the Cavalry under Custer's command certainley did use their sabres, with great success against the Confederate cavalry.
I am somewhat supicious of the figures concerning bullet to knife, to canon ratio kill etc. Unless they looked at every body on the battlefield, they can surely only be a guestimate?