What was the last effort to prevent the south from seceding? blaine amendment washington peace conference montgomery convention missouri compromise

The right answer is the Washington Peace Conference, also known as the Peace Conference of 1861, which, just a few months before the beginning of the American Civil War, brought together, at a hotel in Washington, DC, a group of politicians led by John Tyler that attempted, unsuccessfully, to resolve the crisis that was dividing the nation (over the issue of whether slavery should be limited or protected) so the Union could be preserved.  

hernan cortes;

explanation:

4 copper and gold, the california gold rush is why im pretty sure.