Albert Benjamin Cunningham, teacher and mystery novelist, son of Nathan Decatur and Sarah Ann (Shafer) Cunningham, was born at Linden, West Virginia, on June 22, 1888. His father was an itinerant Baptist minister, and the family moved frequently. During his boyhood, Cunningham roamed the West Virginia hillsides and became an interested observer of flowers, trees, herbs, and other plant life of the region. His observations were later reflected in such works as Old Black Bass (1922).
In June 1905 Cunningham enlisted in the regular army. After serving only two months and three days he was discharged because of a strained heart resulting from dragging a cannon. He enrolled at Muskingum College in New Concord, Ohio, and in 1913 received a bachelor of arts degree. He married Jean Gregory on June 18, 1912. Cunningham received a B.D. degree from Drew University at Madison, New Jersey, in June 1915. He served in pastorates and worked at various other jobs to support himself but decided on a teaching career. He attended New York University and received his M.A. degree in 1916, followed by a Litt.D. from Lebanon (Ohio) University in 1917. In New York he wrote The Manse at Barren Rocks (1917). His academic career was interrupted during World War I, when he volunteered to serve as a chaplain, but he was discharged because he contracted influenza and pneumonia during the epidemic that swept the country. After the war ended, he returned to New York University, where in 1929 he received a Ph.D. in sociology and psychology. He taught English for the rest of his career. He was dean of Lebanon University in 1916–17 and dean of the College of Puget Sound from 1919 to 1922. He taught in the English department at Washington State College from 1922 to 1925, was professor of English at State Teachers College, Shippensburg, Pennsylvania, from 1926 to 1929. In 1929 he accepted a position at Texas Tech University in Lubbock, Texas, where he taught English for twenty years. He retired in 1945 as professor emeritus and subsequently devoted full time to his freelance work.
Cunningham wrote forty-two books on a variety of themes. His twenty volumes of detective fiction, comprising the ABC Mystery series published by E. P. Dutton and Company, were his best known. Only one of his mysteries, Death of a Bullionaire (1947), is set in West Texas, where he spent the last years of his life; the others are set in his native West Virginia. One of his favorite protagonists was a homespun and shrewd Kentucky sheriff, Jess Roden. Cunningham's most popular mystery, Death Rides a Sorrel Horse (1946), was translated into German, Italian, Spanish, and French for printings in Mexico, South America, Canada, and Europe. Several of his mysteries were serialized, and many were included in detective-fiction digests. Because his publisher thought his more serious novels dealing with social problems appealed to a different audience from that of the detective fiction, Cunningham assumed the pseudonym Garth Hale for those works. The Victory of Paul Kent (1948) was perhaps his best-known in this category. He used the pen name Estil Dale to test the appeal of one novel, The Last Survivor (1952).
Cunningham was a member of Tau Kappa Alpha and Pi Kappa Delta. He was a Mason, Odd Fellow, and Knight of Pythias, as well as a Methodist and Republican. He died on September 24, 1962, and was survived by his wife, Jean. They had no children. Cunningham was buried at Resthaven Cemetery in Lubbock.