The three 3 reasons why the US got involved in WWI are
1. Germany invaded Belgium, a neutral country, which made America think that they might invade another neutral country, which is them
2. The Zimmerman Note or The Zimmerman telegraph is a telegraph Germany tried to send to Mexico that they should invade/ attack the US, which was intercepted by the British who told the US about it.
3. Germany sinking our boat, the Lusitania killing 128 Americans because it had war supplies helping their enemies.