How did the conflict about slavery impact political alliances and lead to growth of a new political party

Abolitionists founded the Republican Party in 1854 and those who disagreed with slavery teamed up when the Whig party was failing its base, so they created a new party solely based on the abolition of slavery. Southern and Northern Democrats were mostly for segregation and slavery policies while the Republicans were against slavery and did not want it to spread into new territories the US acquired.