What political party was split on the issue of slavery which eventually caused the party to collapse?

The Whig Party was split on the issue of slavery, leading to its eventual collapse in the 1850s. Internal divisions arose primarily over the Kansas-Nebraska Act, which allowed new territories to decide on the legality of slavery. This fracture resulted in many Northern Whigs opposing slavery, while Southern Whigs supported it, ultimately contributing to the party's dissolution and the rise of the Republican Party.