In World War II, blockbusters were powerful bombs capable of destroying entire city blocks. Hit movies were called blockbusters to show they were shocking, exciting, and impactful.
During the Second World War, the Allies used massive bombs (4,000-12,000lbs) to destroy entire industrial complexes in Axis territory. The troops called the bombs blockbusters for their ability to “bust” entire blocks.
It didn’t take long for movie producers to start describing their movies as blockbusters. In 1943, RKO Pictures became the first production company to use the word in advertising when they described the film Bombardier as “The block-buster of all action-thrill-service shows!” (The hyphen in blockbuster gradually went away as usage of the word became more popular.) For the rest of the war, moviemakers used block-buster frequently, but they almost exclusively reserved it for war dramas. And back then, the term was used to describe excitement in the movie, not box office success.
After the war, use of the term declined, likely in part due to the destruction of Hiroshima and Nagasaki. But filmmakers revitalized the word in the 1970s when Steven Spielberg and George Lucas were instumental in starting the blockbuster genre and the rise of major summer blockbusters.
In 1975, the usage of “blockbuster” for films coalesced around Steven Spielberg’s Jaws. It was perceived as a new cultural phenomenon: a fast-paced, exciting entertainment, inspiring interest and conversation beyond the theatre (which would later be called “buzz”), and repeated viewings. The film is regarded as the first film of the “blockbuster era”, and founded the blockbuster film genre. Two years later, Star Wars expanded on the success of Jaws, setting box office records and enjoying a theatrical run that lasted more than a year.
Some believe the misconception that blockbuster comes from box office lineups stretching around blocks, but historians have traced the first recorded uses of the word back to the gargantuan bombs in the 1940s. (Ironic, since box office blockbusters and box office bombs are opposites)
From 1985-2010, it also meant Blockbuster Video, the defunct movie rental company, but streaming services have taken over its role.