Sorry, Lincoln was NOT a third party candidate. And the reason why is very important.
MrPete
1

Let’s see. The election of 1856 had two parties. Neither of those was the Republican Party. Between 1856 and 1860, the GOP effectively replaced the Whig Party.

On a technicality, the dissolution of the 2nd party made the GOP the 2nd party. For all, and I do mean all, intents and purposes, the upstart GOP was the alternative to the two parties that existed previously.

Options. We need options.