The Crittenden Compromise was a package of six constitutional amendments and four congressional resolutions meant to appease the Southern politicians leading the secessionist movement. Introduced by Kentucky Senator John J. Crittenden, a member of the Constitutional Unionist party, the resolutions sought to guarantee the legality of slavery where it already existed and to return to the Missouri Compromise line for determining its legality in any future territorial acquisitions. The package also included amendments and resolutions to strengthen enforcement of fugitive slave laws and to protect the interstate slave trade. The sixth amendment provided that none of the previous five amendments could be overridden by future amendments. Despite appealing to many Southern legislators, Crittenden’s plan did not pass either house of Congress. President-elect Abraham Lincoln was an especially vocal foe of the measure, and most Republicans followed him in opposing it.