When they had proved unprofitable, after a long period of pointless manipulation--cost, one million dollars--they had been sold to the city for exactly that sum each, it being poetically deemed that a growing city could better afford to lose so disturbing an amount than any of its humble, ambitious, and respectable citizens.

That was a little affair by which members of council had profited years before; but that also is another story.
After discovering these tunnels Cowperwood walked through them several times--for though they were now boarded up, there was still an uninterrupted footpath--and wondered why they could not be utilized.
It seemed to him that if the street-car traffic were heavy enough, profitable enough, and these tunnels, for a reasonable sum, could be made into a lower grade, one of the problems which now hampered the growth of the North and West Sides would be obviated.

But how?
He did not own the tunnels.

He did not own the street-railways.

The cost of leasing and rebuilding the tunnels would be enormous.