From A. Merritt Taylor’s Report of Transit Commissioner, City of Philadelphia. At the time, only the current Market-Frankford Line (complete with “Ferry Line” extension at the east end) was operating, so everything else shown here is proposed. Coincidentally, the colour scheme used seems to be almost identical to that used today, although the colours actually indicate immediacy of construction – blue for extant, orange for “immediate construction” and green for “future construction”.

Source: 18brumaire/Flickr