Chronological Reasoning Wilmot Proviso- he Wilmot Proviso was a proposal to prohibit slavery in the territory acquired by the United States at the conclusion of the Mexican War. In 1846, David Wilmot a Democratic member of the United States House of Representatives from Pennsylvania, proposed the Wilmot Proviso. Mexican American war- The Mexican?American War, also known in the United States as the Mexican War and in Mexico as the American intervention in Mexico, was an armed conflict between the United States of America and the United Mexican States from 1846 to 1848. Fugitive Slave Act- Fugitive Slave Act was passed by the United States Congress on September 18, 1850, as part of the Compromise of 1850 between Southern slave-holding interests and Northern Free-Soilers.