Born in Brunswick (in modern-day Maine, then a part of Massachusetts), Dunlap was educated by private tutors.

Robert Dunlap, was born in 1715 in County Antrim, Ireland and was a Presbyterian minister trained at the University of Edinburgh.

[1] He studied law, was admitted to the bar in 1818, and commenced practice in Brunswick.

He served as member of the state militia, and was delegated to receive General Lafayette when he visited Maine in 1824.

He served as collector of customs in Portland, Maine, in 1848-49, and postmaster of Brunswick in 1853-57.