In 1841 the gun salute was standardized to how many guns

21

Explanation:

Gun Salutes are traditionally used to honor the military and political officials and it was a symbol of trust and respect. Before 1841 The United States national salute consist fire of one gun from each state in the Union. It was a customary practice to that when a foreign vessel arrived at the port of a country to salute the national flag with the guns in that country's national salute. Therefore a need arises for standardized gun salute which was 21 for most of the nations and adopted by the United States as well.