He attended Beaver Academy and Dickinson College in Carlisle, Pennsylvania.

He studied law, was admitted to the bar at Lancaster, Pennsylvania, in 1844 and practiced.

During the American Civil War, Dickey served as lieutenant colonel of the Tenth Regiment, Pennsylvania Volunteers.

Dickey was elected as a Republican to the Fortieth Congress to fill the vacancy caused by the death of Thaddeus Stevens and on the same day was elected to the Forty-first Congress.

He was a delegate to the State constitutional convention at Harrisburg, Pennsylvania in 1873.