Note the details of the stand up collar. The piping around the collar would be in the branch color. The uniform coat was not as comfortable as the sack coat but originally was adopted as an all purpose uniform. Experience showed it was not well suited for fatigue duties and the four button sack coat was introduced in 1857. Having a soldierly appearance was important to both offices and men and the frock coat (uniform coat) is frequently worn in soldier's photographs.