For Further Information, See Source. Source: Bur. Of Bldg. Inspection, Phila. 1890-95: Annual Reports; 1896-1935: Records.
This NBER data series a02057 appears on the NBER website in Chapter 2 at http://www.nber.org/databases/macrohistory/contents/chapter02.html.
NBER Indicator: a02057
Release: NBER Macrohistory Database
National Bureau of Economic Research, Value of Permits For Commercial and Industrial Buildings for Philadelphia, PA [A02057US37980A398NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/A02057US37980A398NNBR/, August 31, 2015.