What event helped cause the eventual split of the Democratic Party, paving the way for the Republican Party and Abraham Lincoln? Kansas choosing to become a free state Nebraska choosing to become a free state the U.S. Supreme Court decision on Dred Scott the Missouri Compromise of 1820
The event that helped cause the eventual split of the Democratic Party, paving the way for the Republican Party and Abraham Lincoln was: Kansas choosing to become a free state This occurrence split the votes for democratic party (those who're pro slavery and those who don't) and helped Lincoln securing his position as a president of united states