What postwar treaty was drafted a the Paris peace conference but was not ratified?

The postwar treaty drafted at the Paris Peace Conference that was not ratified is the Treaty of Versailles, specifically concerning the United States' involvement. Although the treaty was signed in 1919, it faced opposition in the U.S. Senate, primarily due to concerns over the League of Nations and its implications for American sovereignty. Consequently, the U.S. never ratified the treaty, leading to a separate peace agreement with Germany in 1921.