The use of gun salutes for military occasions is traced to early warriors who demonstrated their peaceful intentions by placing their weapons in a position that rendered them ineffective. Apparently this custom was universal, with the specific act varying with time and place, depending on the weapons being used. A North African tribe, for example, trailed the points of their spears on the ground to indicate that they did not mean to be hostile.
The tradition of rendering a salute by cannon originated in the 14th century as firearms and cannons came into use. Since these early devices contained only one projectile, discharging them once rendered them ineffective. Originally warships fired seven-gun salutes--the number seven probably selected because of its astrological and Biblical significance. Seven planets had been identified and the phases of the moon changed every seven days. The Bible states that God rested on the seventh day after Creation, that every seventh year was sabbatical and that the seven times seventh year ushered in the Jubilee year.
Land batteries, having a greater supply of gunpowder, were able to fire three guns for every shot fired afloat, hence the salute by shore batteries was 21 guns. The multiple of three probably was chosen because of the mystical significance of the number three in many ancient civilizations. Early gunpowder, composed mainly of sodium nitrate, spoiled easily at sea, but could be kept cooler and drier in land magazines. When potassium nitrate improved the quality of gunpowder, ships at sea adopted the salute of 21 guns.
The 21-gun salute became the highest honor a nation rendered. Varying customs among the maritime powers led to confusion in saluting and return of salutes. Great Britain, the world's preeminent seapower in the 18th and 19th centuries, compelled weaker nations to salute first, and for a time monarchies received more guns than did republics. Eventually, by agreement, the international salute was established at 21 guns, although the United States did not agree on this procedure until August 1875.
The gun salute system of the United States has changed considerably over the years. In 1810, the "national salute" was defined by the War Department as equal to the number of states in the Union--at that time 17. This salute was fired by all U.S. military installations at 1:00 p.m. (later at noon) on Independence Day. The President also received a salute equal to the number of states whenever he visited a military installation.
In 1842, the Presidential salute was formally established at 21 guns. In 1890, regulations designated the "national salute" as 21 guns and redesignated the traditional Independence Day salute, the "Salute to the Union," equal to the number of states. Fifty guns are also fired on all military installations equipped to do so at the close of the day of the funeral of a President, ex-President, or President-elect.
Today the national salute of 21 guns is fired in honor of a national flag, the sovereign or chief of state of a foreign nation, a member of a reigning royal family, and the President, ex-President and President-elect of the United States. It is also fired at noon of the day of the funeral of a President, ex-President, or President-elect.
Gun salutes are also rendered to other military and civilian leaders of this and other nations. The number of guns is based on their protocol rank. These salutes are always in odd numbers.
The firing of three rifle volleys (rounds) over the graves of fallen armed forces members and political leaders can be traced to the European dynastic wars, when fighting was halted to remove the dead and wounded. Once an area was cleared of casualties, three volleys were sent into the air as a signal to resume fighting.
By about 1730, the British navy was prescribing 21 guns for certain anniversary dates as a personal salute to members of the royal family. This was not mandatory, however. The 21-gun salute was adopted as the standard salute for royalty in 1808.
The United States fired a “national salute,” on special occasions and during times of mourning, of one gun for each state in the union until 1841, when the salute was standardized at 21 guns. It was customary at that time, when naval vessels were visiting foreign ports, to salute the flag of that nation with the number of guns present in the foreign country’s national salute. It would have been difficult, if not impossible, for vessels visiting the United States to fire a salute that, in 1841, doubled the number of guns prescribed by most other nations (42 as compared to 21). Also, it would have been internationally discourteous to offer a salute to a foreign port with fewer guns then prescribed by our own national salute.
The British proposed that the two nations exchange salutes gun for gun when their vessels visited American ports in the nineteenth century. In 1875, the British minister at Washington, D.C., and the U.S. secretary of state decided to work towards an agreement on salutes. On August 18, 1875, the United States formally adopted the 21-gun salute, the number prescribed by Britain, France and other nations.
No one can explain why the number 21 was chosen for national salutes. In ancient cultures, numerology, the study of numbers, developed symbolism behind most numbers. These cultures believed the number seven to be sacred and, therefore, it is believed, multiples of seven would be looked upon favorably (hence 21). Other gun salutes vary from five guns (the lowest) to 21 guns (the highest) by increments of two, and are prescribed in accordance with occasion and level of importance of those honored. It is generally believed that gun salutes are set off in odd numbers because of an old naval superstition that even numbers are unlucky.