The Republican Party, early named Liberian Party, was a political party founded soon after the establishment of Liberia in 1848. It was known to be made up primarily of Americo-Liberians who had mixed African and European ancestry. Its main opponent was the True Whig Party.
The Republican party was founded between 1845 and 1850.
It's true because it is founded in 1848 between 1845 and 1850, Reason is system is looking for an absolute year to mark it correct.