 Complete the following phrase:  Between 1847 and 1980, the presidency was exclusively held by Americo-Liberians, the original American settlers of Liberia and their descendants. The original two-party system, with the Republican Party and the True Whig Party, ended in 1878, when the election of Anthony W. Gardiner marked the beginning of 102 years of one-party rule by the True Whigs. Following a 