How did the westward movement contribute to the civil war?

The westward movement intensified sectional tensions between the North and South, primarily over the expansion of slavery into new territories. The debate over whether new states admitted to the Union would be free or slave states led to significant conflict, exemplified by events like the Missouri Compromise and the Kansas-Nebraska Act. This struggle for power and representation heightened animosities, as both sides sought to protect their interests, ultimately contributing to the outbreak of the Civil War. The westward expansion also fostered a sense of manifest destiny, which further entrenched divisive ideologies in American society.