Camden also experienced dramatic shifts in its population demographic. Immigration from Eastern Europe made them the leading ethnic group by 1920, whereas it had previously been German, British, and Irish immigrants. In 1926, a bridge connected New Jersey and Pennsylvania made its debut opening, which was named the Benjamin Franklin Bridge in 1956. The project cost $37 million, which New Jersey and Pennsylvania both paid equal parts of. The goal was to reduce ferry traffic between Philadelphia and Camden. Camden Central Airport opened in 1929 (closed in 1957).