Who was the first democratic-Republican Party candidate?

According to the official history of the Republican Party, the Republicans became a national party in 1856, nominating John C. Fremont for President. That election effort failed but the Grand Old Party (GOP) succeeded four years later with the election of Abraham Lincoln in 1860. With Lincoln's election, the Republican Party became firmly established as a major political party.

FYI - The name "Republican" was chosen because it alluded to equality and reminded individuals of Thomas Jefferson's Democratic-Republican Party."GOP" is often used as a substitute reference to the Republican Party. "GOP" is an acronym for "Grand Olde Party."