He is considered one of the leaders in developing a multi-party system in Liberia, long dominated by the True Whig Party.
In 1975 he and many among the Liberian diaspora formed the Progressive Alliance of Liberia (PAL), the first legal opposition party to be recognized in decades.
After the April 1980 coup in which Tolbert was overthrown and Samuel K. Doe came to power, Matthews was appointed as Minister of Foreign Affairs for the first time.
At the end of the civil war, Matthews stood unsuccessfully as the candidate of the United People's Party in the 1997 presidential election.
Knowing that he was ill, and rejected by some politicians, Matthews told his wife, then in the United States, to ask Monsignor Father Robert Tikpor of the Catholic Church to give his eulogy.