In the middle 1800s what issue divided the political parties Which two parties remained after the Civil War?

In the middle 1800s, the primary issue that divided the political parties was slavery, particularly its expansion into the western territories. This contentious debate led to the fracturing of the Whig Party and the rise of the Republican Party, which opposed the spread of slavery. After the Civil War, the two main political parties that remained were the Republican Party, which largely supported Reconstruction and civil rights for freed slaves, and the Democratic Party, which often upheld Southern interests and resisted Reconstruction efforts.