He served as colonel in the Louisiana Militia in 1876. In November of that year, claiming voting fraud, he and other Democrats objected to the reelection of Republican Chester Bidwell Darrall to represent Louisiana's 3rd congressional district; after protracted settlement of the various controversies surrounding the 1876 presidential election, on February 20, 1878, Darrall left the seat and was replaced by Acklen, for the remaining half of the Forty-fifth Congress. Acklen was reelected, to the Forty-sixth Congress, and served from 20 February 1878 to 4 March 1881. He was not a candidate for renomination in 1880, and Darrall regained the seat for one term (the Forty-seventh Congress).