A graduate of Liberia College, Johnson became a skilled building contractor and Brigadier General in the national militia. He twice served as Mayor of Monrovia (1912–1913, 1920–1921), and led Liberia’s chapter of Marcus Garvey’s UNIA as its Supreme Potentate. In this role, he represented Liberia at international conventions, advocated for African self-determination, and challenged foreign influence, earning both reverence and resistance.