From The Atlantic's profile of George Lucas, in 1979:
The idea of Star Wars was simply to make a "real gee-whiz movie." It would be a high adventure film for children, a pleasure film which would be a logical end to the road down which Coppola had directed his apparently cold, remote associate. As Graffiti went out around the country, Lucas refined his ideas. He toyed with remaking the great Flash Gordon serials, with Dale Arden in peril and the evil Emperor Ming; but the owners of the rights wanted a high price and overstringent controls on how their characters were used. Instead, Lucas began to research. "I researched kids' movies," he says, "and how they work and how myths work; and I looked very carefully at the elements of films within that fairy-tale genre which made them successful." Some of his conclusions were almost fanciful. "I found that myth always took place over the hill, in some exotic, far-off land. For the Greeks, it was Ulysses going off into the unknown. For Victorian England it was India or North Africa or treasure islands. For America it was Out West. There had to be strange savages and bizarre things in an exotic land. Now the last of that mythology died out in the mid-1950s, with the last of the men who knew the Old West. The last 'over the hill' is space."