Answer:
The United States initially remained neutral in World War I, but several factors contributed to its eventual entry into the war on the side of the Allies, including Britain. These factors include:
1. Unrestricted Submarine Warfare: Germany's use of unrestricted submarine warfare, particularly the sinking of the British ocean liner Lusitania in 1915, which killed American civilians, created outrage in the U.S.
2. Economic Interests: The U.S. had economic ties with the Allied Powers, particularly Britain and France. American businesses had substantial financial interests in these countries, and the U.S. loaned significant amounts of money to the Allies.
3. Propaganda and Public Opinion: Propaganda campaigns and public opinion swayed Americans toward the Allied cause, portraying the Central Powers, including Germany, as aggressors.
4. Zimmermann Telegram: The interception of the Zimmermann Telegram, in which Germany proposed a military alliance with Mexico against the United States, further pushed the U.S. toward involvement in the war.
5. Cultural and Linguistic Ties: Many Americans had cultural, linguistic, and ancestral ties to the nations of the Allied Powers, making their cause more sympathetic to the American public.
These factors culminated in the United States officially declaring war on Germany and entering World War I on the side of the Allies in April 1917.