For a time, there was even only one major party with different factions within it. The Whig and Democratic parties only started when Democratic-Republicans loyal to J Q Adams split from those loyal to Andrew Jackson. Jacksonians became "Democrats" and the Adams faction took the name "Whig." The Democrats are the same organization to this day. The Whigs split apart over the slavery issue in the 1850s, Northern Whigs regrouped as "Republicans," which is the GOP we have now.