"An article in Hyperallergic caught my eye when I read, "The New York Public Library Has a 'Digital Time-Travel Service' for Its Historical Maps." I had to check it out. It seems the New York Public Library has a two year project to plot 5,000 digitized street maps across the five boroughs, organized by decade from 1850 to 1950.
The article states that the "New York Public Library’s new NYC Space/Time Directory is imagined as a 'digital time-travel service,' a two-year project engaging the library’s collections of maps and geospatial data through interactive tools." The first tool, Maps by Decade, was launched this month.
“The goal of the Space/Time project is to connect the library’s collections through space and time,” Bert Spaan, NYPL’s Space/Time Directory engineer, told Hyperallergic. Now that is pretty cool. If your ancestor came through Ellis Island they may have lived in NYC for a time. If you are really lucky, you might just be able to view the exact location "real time." Happy hunting!