The firing of three volleys over the grave of a soldier can be traced back to the Roman Empire. The multiple of three probably was chosen because of the mystical significance of the number three in many ancient civilizations. After the burial rites, the Romans would shout the name of the deceased three times followed by the word “vale”(farewell) to insure that it would never be forgotten. There is also a practice of throwing three spadeful of dirt onto a coffin. The practice of firing volleys may have originated in the old custom of halting the fighting to remove the dead from the battlefield. Once each army had cleared its dead, it would fire three volleys to indicate that deceased soldiers had been cared for and that the army was ready to resume the fight. Although I must admit I have never found a written reference to this ever happening. And I’ve not seen this in any type of manuals. The closest I’ve seen is the call or signal for a parley. The tradition of firing the three volleys at funerals was noted in regulations and manuals. There was no original number of rifles called for in a rifle salute. There are photos of funerals at Arlington in the late 19th century were the entire platoon is firing. In modern-day ceremonies, the fact that the firing party consists of seven riflemen firing three volleys does not constitute a twenty-one gun salute; that is only rendered by cannon firing twenty-one times.