"Originally, I thought this was early 1960s night shot showed a CTA single-car unit in the 1-50 series, and those cars were used on the Congress-Douglas-Milwaukee line. But as Andre Kristopans has pointed out, the doors on those cars were closer to the ends than this one, which he identifies as being part of the 6511-6720 series. It just looks like there's one car, since the other ""married pair"" behind it is not illuminated. This picture was most likely taken at the end of the line at DesPlaines Avenue. Anyway, this prompted some interesting correspondence with Andre Kristopans on the Philly Traction Yahoo Group."
{}