He came from a highly respected family in St. James and showed every prospect of having a successful career in the Civil Service, but by 1910 he had made the momentous decision to go to the United States to study theology and be ordained into the Unitarian Church.  Since his early teens he had rejected the Trinitarianism of the mainstream churches and had decided that only Unitarianism represented his religious beliefs.

He returned to Jamaica in 1912 and tried for eight years to establish a Unitarian church in Jamaica: the American Unitarians were ambivalent about this effort and only gave him limited and grudging support.  During those years he was also involved in many other organisations in Jamaica, including the Jamaica League and the U. N. I. A. His relationship with Garvey was always uneasy and later he was a staunch opponent of the Garvey movement.  By 1920 he was unable to continue his mission in Jamaica and decided to go to Harlem to set up a Unitarian church there.

Brown's church in Harlem never had a large membership and he continued to have serious difficulties in his relationship with the Unitarian Church authorities.  However the church was an important center for debate on current issues in the community and Brown, along with other West Indians, was a strong voice for progressive opinion.  He was in fact one of the founding members of the Jamaica Progressive League and for some 20 years its Secretary. He represented the League before the Moyne Commission in 1938. He also became an important supporter and fund-raiser for the P. N. P. in the United States.  He worked closely with Norman Manley and visited Jamaica in the summer of 1952 in the aftermath of the expulsion of four leading left wingers. When he died in 1956 appreciation for his work was expressed in obituaries in the local papers.