The Cirkers started the business selling remaindered textbooks by mail from their apartment in Queens, New York City. The company published its first book, "Tables of Functions with Formulas and Curves", when the German copyright was voided by the United States as a result of World War II. The book was an unexpected success and established the Dover business model of publishing esoteric works at a low price. One of Dover's best sellers was Albert Einstein's "The Principle of Relativity", which Einstein reluctantly agreed to republish despite his concerns that it was outdated.