Curious to know where J.D. Salinger lived in Manhattan? As of midnight on Wednesday, Americans can perform a name search on an online census to access personal data about New York state residents dating back to 1940. Previously, users needed to provide the exact addresses of the person they were searching for on the free census site, Ancestry.com. The new technology will allow people across the country to trace their family trees to immigrants who came to the U.S. through Ellis Island. New York census data from 1915 and 1925 is now also accessible online to anyone with a New York ZIP code.