Why did the U.S congress oppose the signing of the treaty of versallies?

The U.S. Congress opposed the signing of the Treaty of Versailles primarily due to concerns over the League of Nations, which many lawmakers believed would entangle the United States in foreign conflicts and compromise national sovereignty. There was also significant political opposition from isolationist factions and the Republican Party, which felt the treaty was too harsh on Germany and did not adequately protect U.S. interests. Ultimately, these factors led to the Senate rejecting the treaty in 1919.