In April 1877, the New York City Board of Alderman passed a resolution requesting that Commissioner Campbell assess the feasibility of constructing an underground line from City Hall to the existing line by private enterprise. The Commissioner was strongly in support of such a plan, and predicted that such a line would have a daily ridership of 100,000, would make $1.8 million annually and would cost $9 to $10 million to build–in his mind, a financial success. William Vanderbilt was criticized for not following through on the plans of his father to extend the line to City Hall.