Louis Prang, a Bavarian-born lithographer who immigrated to America in 1850, is known as the 'Father of the American Christmas Card.' He perfected chromolithography—a technique for reproducing color oil paintings—and began mass-producing Christmas cards in 1875. His cards featured elaborate designs of flowers, children, and winter scenes, and became so popular that by the 1880s, he was printing five million cards per year.