He studied at the Royal School Dungannon and later at Queen's University of Ireland, from where he graduated in 1852.

He was awarded a Doctor of Sacred Theology from Racine College in 1880.

He also served as dean of the St Louis Convocation of the Diocese of Missouri and deputy to the General Convention of 1871, 1877 and 1880.

Dunlop was elected Missionary Bishop of Arizona and New Mexico in 1880 and consecrated on November 21, 1880, by Bishop Henry Benjamin Whipple of Minnesota in Christ Church, St. Louis.

Dunlop married Mary Wickham Cobb on July 23, 1857, and had seven children.