Matt, unless circumstances (sickness, detached duty, etc.) took him elsewhere, the soldier would be with his regiment. I have many, many entries in my Arkansas soldiers database for (mostly) U.S. volunteers who records indicate that they were killed in action, died of disease, deserted, were discharged, etc., followed by the notation, "Remarks: Never mustered."

I regret that I've never found the time to inquire as to why there was often such a long gap between enlistment and muster. Maybe someone will post something that can enlighten us?