A New Hope Considered as a Standalone
Early drafts of Star Wars: A New Hope saw the film as a self-contained body, with the Death Star's destruction brinigng down the entire Empire. But, as Lucas stated in 1994, "It wasn't long after I began writing Star Wars that I realized the story was more than a single film could hold. As the saga of the Skywalkers and Jedi Knights unfolded, I began to see it as a tale that could take at least nine films to tell - three trilogies - and I realized, in making my way through the back story and after story, that I was really setting out to write the middle story." Plus, hey, after the runaway success of the first film, there just had to be a sequel, whether it was already conceived that way, or not.