Some think that comic book culture is a modern phenomenon. Yet, the 1966 television schedule was a sci-fi and comic lover's dream. In the wake of James Bond, the spy genre was booming, too. Mission: Impossible, Get Smart, The Man Who Never Was, I Spy and The Avengers were all fighting the Cold War with gadgets and secret agent skills. And then, of course, there was The Man from U.N.C.L.E., America's first spy show.

When The Man from U.N.C.L.E. premiered in 1964, the TV Guide schedule was a landscape of sitcoms. The popularity of the show signaled a sea change in programming. Over the course of its four seasons, The Man from U.N.C.L.E. underwent drastic changes as well — as we'll get to below — making it arguably the definitive action series of the decade. 

Here are six reasons The Man from U.N.C.L.E. is the coolest spy show of the 1960s — even when it became the silliest. 

1) Like James Bond, Napoleon Solo and April Dancer were the brainchildren of Ian Fleming.

2) It is technically set in the Sherlock Holmes universe. 

3) William Shatner and Leonard Nimoy appeared in an episode together — years before Star Trek.

4) It was three dramatically (and comedically) different shows in one. 

5) A famous board game inventor designed the weaponry.

6) The United Nations made the writers come up with the acronym for U.N.C.L.E.