It's an unusual decision, because most countries base their holidays around when the first battles occur. The French celebrate Bastille Day, which is July 14th. But in the USA there are no celebrations on April 19th, which is a bit surprising. The heroism shown at the battles of Lexington and Concord are forgotten, whereas a bunch of men signing a document is raised to the level of something epic. And it is said that the USA began in 1776, instead of 1775. If the French followed such reasoning, they would say that the French Revolution began on September 20th, 1792, because of the Battle of Valmy.
To suggest that the USA begins on July 4th of 1776 represents a victory for Thomas Jefferson, and for the factions associated with him. The key thing is that Jefferson's factions were very popular during the 1810s and 1820s, when Americans were making up their minds about how they should understand the origin of the country.
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