Republican Party:

The Republican Party had its start in the year 1854 by anti-slavery expansion activists and modernizers. Up until the 1860 election, the Republican party had been gaining prominence, but it wasn't really a major threat to the dominating Democrat party. It was in that 1860 election that the Democrats split into four factions and thus the Republican nominee, Abraham Lincoln took the office. Only months later, the country was plunged into the Civil War. Republicans would take the Senate and House through the next election cycle, Abramham Lincoln was assassinated, and turmoil over the South's reconstruction would wage on for years.

The party dominated the Presidency, with just one Democrat having the White House from 1860 to 1912.