Rev. Van Horne was Pastor at Union Colored Congregational Church between 1868 & 1896. This church was established in 1824 as a religious extension of the 18th century Free African Benevolent Society.
Later Van Horne became the first African American on the Newport School Board in 1871 and the first African American to serve in the RI General Assembly in 1885. In 1898 he was appointed General Counsel to Danish West Indies by President McKinley during Spanish American War.