In my opinion, the Civil War was inevitable. Now, if Andrew Jackson would've been President during 1861 he would've simply delayed the Civil War by some years. If the slavery question is not answered by the executive office then either the North or the South will secede depending on who the succeeding presidents sides with. If the majority of the presidents sides with the South then the North secedes and that spells the end of the Union and if the majority of the presidents sides with the North then the South secedes and depending on how many years have gone by then the war would've been bloodier and more lives would've been lost.
If Breckinridge, Crittenden, Bayard, or even Bell had somehow won in the 1850s or 1860s, what states do you think would secede? I assume New England, New York, New Jersey, and Pennsylvania, but what of the Midwest and West?