David Dortort, a television writer and producer whose idea to create a western drama based not on shoot-’em-ups but instead on the travails of a loving family resulted in “Bonanza,” one of the most popular shows in history, died on Sunday in Los Angeles. He was 93.

The cause was uncertain, but he had a history of heart problems, said his daughter, Wendy Czarnecki.

In 1958 Mr. Dortort, an experienced television writer, had also become one of the first writer-producers in television drama. He was serving both functions on a successful half-hour western, “The Restless Gun,” starring John Payne in the traditional Hollywood role of a roving gunman who settles the conflict in each episode — and establishes right and wrong — by shooting the bad guy.

The show was broadcast on NBC, and that network asked Mr. Dortort to develop a western for NBC itself to produce, an opportunity that Mr. Dortort, who studied American history at City College of New York and believed his familiarity with the subject was the equal of that of anyone in Hollywood, seized upon to combat what he called “the myth of the lone gunfighter.”

He pitched a show set on a Nevada ranch on the shore of Lake Tahoe after the 1859 discovery of the gold and silver deposits known as the Comstock Lode in Virginia City. Rather than focusing on a single hero, the show would have four: a father, widowed three times, and his three sons. The idea of “Bonanza,” as the show came to be called, was to depict the story of the American West — “one of the great migrations of all time,” he called it — with accuracy.

“The gunfighter played a small, inconsequential role in the story of the West,” Mr. Dortort explained in a 2002 interview with the Archive of American Television. “The true history of the West is about family, pioneers.”

Because the show was to be partly shot on location, and because color television sets were on the verge of being readily available to consumers, Mr. Dortort urged the network to film “Bonanza” in color, and it became television’s first full-hour western in color, which helped distinguish it from competitors like “Laramie” and “Gunsmoke.” It starred Lorne Greene as Ben Cartwright, the family patriarch (whom Mr. Dortort named after his own father), and, as his sons, Pernell Roberts as the eldest and the most intellectual, Adam; Dan Blocker as the sweet-tempered giant Eric, better known as Hoss; and Michael Landon as the impetuous, hotheaded Little Joe.

“Bonanza” appeared for the first time at 7:30 p.m. on Saturday, Sept. 12, 1959, opposite “Perry Mason” on CBS. Two years later it moved to 9 p.m. on Sunday and became a dominant hit, running for 14 seasons — including three years, from 1964 to 1967, when it was the most-watched television show in the country.

Mr. Dortort oversaw production of the show for most of its run. In addition to telling stories based on historical events involving the Comstock Lode and the oncoming Civil War, the show dealt with themes like racial prejudice and religious tolerance. Mostly, though, its drama, and its popularity, were because of its focus on the Cartwrights and their tight knit bond.

“What is the message?” Mr. Dortort said. “Love is the message.”

David Solomon Katz was born in Brooklyn to Jewish immigrant parents from Eastern Europe on Oct. 23, 1916, and grew up in a neighborhood famous for the gangsters of Murder Inc., a milieu he mined for one of his two novels, “Burial of the Fruit” (1947). His second book, “The Post of Honor,” came out two years later. His father, Beryl Dortort, who came to this country, according to family lore, to avoid going to rabbinical school, changed his name to Benjamin Katz and became a successful insurance salesman.

Young David graduated from Boys High in Brooklyn and City College, where he studied not only history but also creative writing and was a writing-seminar colleague of Alfred Kazin. He met his future wife, Rose Seldin, an accountant, after he graduated. They married in 1940. It was she who persuaded him to change his name back to his father’s original one.

Drafted after the attack on Pearl Harbor, he served in special services in Torrance, Calif., starting a newspaper and arranging for performances by Hollywood entertainers at an Army hospital. “Burial of the Fruit” was optioned for a film, and he was hired to write it, but it was never made, an experience that made him determined to learn how to write for the screen.

His early movie credits include “The Lusty Men” (1952), a western, directed by Nicholas Ray and starring Susan Hayward and Robert Mitchum, and “A Cry in the Night” (1956), a police drama about a kidnapping, with Natalie Wood. His television work included episodes of “Racket Squad” and “Lassie,” and adaptations of the Walter Van Tilburg Clark novel “The Ox-Bow Incident.” In 1967 Mr. Dortort turned his primary focus away from “Bonanza” to create a second western drama, “The High Chaparral,” set in the 1870s in the American Southwest and starring Leif Erickson as the head of another fragmented ranch family. That show ran for four years.

Mr. Dortort’s wife, Rose, died in 2007. In addition to his daughter, who lives in Petaluma, Calif., he is survived by a brother, Elliot Katz, of Marlboro, N.J.; a son, Fred Dortort, of Berkeley, Calif.; and a step-granddaughter.