Which war was fought to gain independence from Britain?

The American Revolutionary War was fought between 1775 and 1783 and primarily aimed at achieving independence from British rule. The colonies in North America sought to break free from the political and economic constraints imposed upon them by the British government, which included taxation without representation and various acts that limited colonial autonomy. After a series of battles and significant events, the war culminated in the signing of the Treaty of Paris in 1783, which recognized the sovereignty of the United States.

The other options, while significant in their own contexts, did not focus primarily on independence from Britain. The Civil War was about internal divisions in the United States, World War I involved a struggle among many nations and was not centered on American independence, and the War of 1812 was primarily a conflict with Britain over maritime rights and other grievances, not about secession from British control, which had already been achieved through the Revolutionary War. The focus on independence in the American Revolutionary War makes it the clear and correct answer to this question.