Answer: They fought because they didn't have self-government. When the American colonies formed, they were part of Britain. Britain increased taxes for colonists on things they bought and used every day, like tea. Many colonists were angry because no one represented their needs in the British government. By issuing the Declaration of Independence, adopted by the Continental Congress on July 4, 1776, the 13 American colonies severed their political connections to Great Britain. The Declaration summarized the colonists’ motivations for seeking independence. By declaring themselves an independent nation, the American colonists were able to confirm an official alliance with the Government of France and obtain French assistance in the war against Great Britain.