In 1775, Hall and fourteen other free blacks joined a British army lodge of Masons who were stationed in BostongAfter the British departed, they formed their own lodge, African Lodge No. 1, though it would be twelve years before they received a permanent charter. Hall became the lodge's first Grand Master.

Hall was active in the affairs of Boston's black community, using his position as "Worshipful Master" of the black Masons to speak out against slavery and the denial of black rights. For years, he protested the lack of schools for black children and finally established one in his own home.

In his last published speech, his charge to the African Lodge in June 1797, Hall spoke of mob violence against blacks: "Patience, I say; for were we not possessed of a great measure of it, we could not bear up under the daily insults we meet with in the streets of Boston, much more on public days of recreation. How, at such times, are we shamefully abused, and that to such a degree, that we may truly be said to carry our lives in our hands, and the arrows of death are flying about our heads....tis not for want of courage in you, for they know that they dare not face you man for man, but in a mob, which we despise..."

Prince Hall died in 1807. A year later, his lodge honored him by changing its name to Prince Hall Grand Lodge.