Sikhism is a religion originating from medieval India (predominantly from the Punjab region of modern-day India and Pakistan) which was introduced into the United States during the 19th century. In 2007, there were estimated to be between 250,000 and 500,000 Sikhs living in the United States, with the largest populations living on the East and West Coasts, together with additional populations in Detroit, Chicago, Houston, Dallas, and Indianapolis. The United States also has a number of non-Punjabi converts to Sikhism.