Meaning of relativity

In 1921, five years after the appearance of his comprehensive paper on general relativity and twelve years before he left Europe permanently to join the Institute for Advanced Study, Albert Einstein visited Princeton University, where he delivered the Stafford Little Lectures for that year. These four lectures constituted an overview of his then controversial theory of relativity. Princeton University Press made the lectures available under the title 'The Meaning of Relativity,' the first book by Einstein to be produced by an American publisher.