This is a very common issue in NYC, my building is also listed as built in 1900. Someone with real estate knowledge told me a fire destroyed many building records (not sure when), so the city defaulted those records to 1900.
edit: I just read this somewhere: "But a word of caution. Buildings built before 1900 are often labeled 1899 or 1900 in city databases." So there may be two separate issues at play here.
Does the nyc opendata initiative have any crowd sourced programs to repair broken records? Could be a win/win for developers and the city if they would accept feedback on their datasets.
Unfortunately gov has for the most part been reluctant to adopt such practices so far. However NPS Maps have been using crowdsourced data from OpenStreetMap and park visitors in their map products.
edit: I just read this somewhere: "But a word of caution. Buildings built before 1900 are often labeled 1899 or 1900 in city databases." So there may be two separate issues at play here.