What was the result of the U. S. Senate's refusal to approve the Treaty of Versailles?

The result was that the Treaty of Versailles could not be passed. The Senate needed a two-thirds majority to pass the treaty, but the Republicans were vehemently opposed to passing the treaty, because they felt they needed more reservations were needed and did not like the idea that the League of Nations could declare a war without asking for a vote by the U. S. Congress. There was also significant opposition by the Irish Catholics and German Democrats who felt this was giving too much power to Britain. As a result, the treaty was never ratified, but separate agreements were signed.