Hope you have a wonderful 4th of July, my friends!
From Wikipedia, we find that ...
Independence Day of the United States, also referred to as Fourth of July or July Fourth in the USA, is a federal holiday commemorating the adoption of the Declaration of Independence on July 4, 1776, which was the date the United States formally declared its independence from Great Britain in order to achieve freedom from British rule.
It's is commonly associated with fireworks, parades, barbecues, ball games, family reunions, and ceremonies, in addition to various other public and private events celebrating the history, government, and traditions of the United States.
Independence Day itself has nothing to do with the military, or soldiers.