*Party division totals are based on election day results.
The aftershocks of the war with Mexico rocked the 31st Congress (1849–1851). Mexico’s massive land cession to the United States precipitated a major sectional crisis over slavery in the new territory. Sectionalism in the House prevented the election of a Speaker for three weeks at the opening of the Congress. This relegated the House to a secondary role during the crisis. The focus instead turned to the Senate which initiated a complicated package of nine bills—known as the Compromise of 1850. The Compromise made an arduous, tangled journey to congressional passage in the fall of 1850.