There was a time when rural comedians drew most of their humor from tales of farmers' daughters, hogs, hens, and hill country high jinks. Lum and Abner and Ma and Pa Kettle might not have toured happily under the "Redneck" marquee, but they were its precursors. In "Ain't That a Knee-Slapper: Rural Comedy in the Twentieth Century," author Tim Hollis traces the evolution of this classic American form of humor in the mass media, beginning with the golden age of radio, when such comedians as Bob Burns, Judy Canova, and Lum and Abner kept listeners laughing. The book then moves into the motion pictures of the 1930s, 1940s, and 1950s, when the established radio stars enjoyed second careers on the silver screen and were joined by live-action renditions of the comic strip characters Li'l Abner and Snuffy Smith, along with the much-loved Ma and Pa Kettle series of films. Hollis explores such rural sitcoms as "The Real McCoys" in the late 1950s and from the 1960s, "The Andy Griffith Show," "The Beverly Hillbillies," "Green Acres," "Hee Haw," and many others. Along the way, readers are taken on side trips into the world of animated cartoons and television commercials that succeeded through a distinctly rural sense of fun. While rural comedy fell out of vogue and networks sacked shows in the early 1970s, the emergence of such hits as "The Dukes of Hazzard" brought the genre whooping back to the mainstream. Hollis concludes with a brief look at the current state of rural humor, which manifests itself in a more suburban, redneck brand of standup comedy. Tim Hollis is the author of numerous books, including "Hi There, Boys and Girls America's Local Children's TV Programs" and (with Greg Ehrbar) "Mouse Tracks: The Story of Walt Disney Records."