With the rise in socially responsible programming, the television western, a very popular genre in the 1960s, slowly died out. The first casualties were "The High Chaparral" and "The Virginian", both NBC staples, in the spring of 1971. "Bonanza" suffered a blow when actor Dan Blocker died during surgery in 1972, and the show quietly ended its run the next year. CBS's "Gunsmoke" outlasted them all, and finally ended its run with a star-studded series finale in 1975. "Bonanza" actor Michael Landon helped popularize a television adaptation of the popular children's book series "Little House on the Prairie". Debuting in 1974, the series ran for eight years. "Little House"'s competitor family drama was CBS's "The Waltons", which revolved around family unity but during a different time and place — Virginia during the Great Depression.