There's an argument to be made that the original Star Trek, which premiered on Sept. 8, 1966, is the most influential television show of all time.

Its effect on the world of science fiction, both on and off the screen, was monumental and continues today. But it also helped pioneer concepts that have become standards (or sometimes just aspirations) in the industry. It featured a radical (for the time) approach to casting and race relations, tackled social issues and pushed the boundaries of what was acceptable to think about those issues, and also helped develop an ensemble approach to storytelling that is now a common feature of the genre.

The show was created by Gene Roddenberry, whose colorful career and longtime love of science fiction helped influence the show. Born in 1921, Roddenberry served as a pilot in the air force during World War II and then worked as a pilot for Pan American Airways after the war. In the course of his flying career, he experienced three plane crashes, including one in which the Pan Am flight he was co-piloting crashed into the desert in Syria.

Watch the 'Star Trek' Opening Credits

In 1948 he decided on a career change and returned to Los Angeles – where he had grown up – to join the Los Angeles Police Department, working first as a traffic cop and then as a speech writer. This latter job led him into advisory work on TV shows in Hollywood, and in 1956 he resigned from the police force and moved into writing for television full time.

Roddenberry worked on a number of shows in the '50s and '60s, and eventually began to develop an idea of his own, centered on a protagonist he thought of as a "space-aged Horatio Hornblower" (after the protagonist of a series of novels by C.S. Forester about a 19th-century Royal Navy officer). He pitched this idea to the production company founded by Desi Arnaz and Lucille Ball called Desilu Productions, and they eventually helped get the show onto NBC.

Watch Captain Kirk in Action on 'Star Trek'

In many ways, Star Trek was based on already existing materials. Roddenberry's own experience as a pilot in the military and as a civilian certainly influenced the show's strong sense of the importance of the chain of command. James T. Kirk (William Shatner) is the captain and the undoubted leader of the show's ship, the USS Enterprise, but many of the episodes in the show's three seasons revolve around the difficulties inherent in the position, from being the one responsible for decisions to having to learn when to delegate authority.

The show also draws from the TV westerns Roddenberry had worked on, taking a basic story familiar to the fans of that genre: a group of adventurers exploring a wild land (as the American west was viewed by Hollywood in those days) filled with unfamiliar people, unexpected dangers and surprising encounters. In this sense, Kirk and his crew members resemble the gunfighting heroes of the Old West, confronting bad guys with a strong sense of justice and a six-gun (or in this case a phaser).

The show also helped develop in a trope of '60s television, in which a group of people engage in adventures that also push them into becoming a surrogate family unit. Like Gilligan's Island, Hogan's Heroes, M*A*S*H and many other shows of the time, Star Trek was fascinated by the way people who are thrown together by circumstance interact with one another.

A large part of the fun of the show comes from the way Kirk wrangles the various personalities under his command, like the logically dominated Spock (Leonard Nimoy) or the obstreperous Dr. "Bones" McCoy (DeForest Kelley), as well as the way they wrangled him. This back-and-forth added layers of complexity to the show's stories and also offered a perfect platform for examining one of its major themes: personal and social difference.

Watch Spock in Action on 'Star Trek'

It's here Star Trek broke the most ground. Earlier shows like The Twilight Zone had dealt with social critique (often as a way of scaring or titillating viewers), but Star Trek urged its audience not only to confront the issues of society but also to imagine a future in which those problems had been overcome. Many of its episodes pushed beyond sci-fi or western tropes of strange creatures or good vs. evil to confront larger questions about how cultures should be organized, whether they should be interfered with from outside, the dangers and lessons of history and the like.

Beyond this the casting of the show was revolutionary at the time, including both a woman of color (Nichelle Nichols playing Uhura) and an Asian-American (George Takei playing Sulu) in large supporting roles. While there were hard limits to the amount of diversity that appeared on the screen – the main protagonists of the show were all white and male – the avowed ethos of the show, spurred by Roddenberry, was one of an egalitarian, multiethnic world. (His initial idea was to have Kirk's second-in-command be a woman, but this was nixed by studio execs.)

This idea of a society in which diversity is a cornerstone of strength – Roddenberry termed it IDIC, for "infinite diversity in infinite combinations" – became one of the central elements of the Star Trek story. It animates large swaths of the huge corpus of shows and movies that have descended from it – including more than a half-dozen spin-off television series, animated shows, more than a dozen movies and projects seemingly always in development – but has also had an immeasurable influence on the way television shows confront the society they emerge from.

Watch Captain Kirk's Best 'Star Trek' Fights

That's not to say that the original show is perfect in either idea or execution. There are plenty of flaws, and the list of ridiculous and silly moments in the show is amazingly long. But almost no TV show is going to look modern and cool more than half a century after it debuts.

Despite these occasional absurdities, what Star Trek managed is something not accomplished by many shows in the history of television: It created an immersive world and indelible characters, and left the medium changed forever.

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