Those wacky Brits and their facts… from The Observer:
As its title makes plain, Bernstein and Sondheim’s musical West Side Story is set in Manhattan’s West Side, not the Lower East Side, as we said in ‘Now try this’ (Review, last week). In Jerome Robbins’s original conception, the star-crossed lovers were to have been a Jewish girl and an Italian Catholic boy, with the action set in the Lower East Side. Hence the title might have been East Side Story. The idea was later changed to the West Side story of American and Puerto Rican gangs. And it opened in 1957, not 1961 (the year of the film’s release).
Even with me being a huge fan, I didn’t know the orignal storyline….