During the American Civil War Fisher and Fremont both joined the Confederate States Army. Fisher became a Colonel commanding the 6th North Carolina Infantry Regiment. He died leading a charge on a Union Army battery at the First Battle of Bull Run, supporting North Carolina General Thomas Lanier Clingman as well as Fisher's cousin (who became General after that battle) Jubal Early. Whether the fatal bullet was from friendly fire of the Fourth Alabama or Second or Eleventh Mississippi, or from the New York Zouaves or other Union soldiers from the Sudley Road will never be known.