So based on all the responses, it seems the answer to the question, “no slavery, no civil war?” is yes. If slavery did not exist then the Deep South would not have seceded and the North would not have claimed a need to preserve the Union. The purpose of the question was to gauge the importance of other issues for secession, such as the protective tariff, but since no other reason for secession by the Deep South was brought up I can assume any other reason was secondary.
