<blockquote>In 1899, Illinois Telephone and Telegraph laid telephone cables through Chicago by building a network of underground tunnels. A narrow gauge railway was laid to assist with excavating the tunnels and installing the cables but the system was quickly adapted and used as a means for transporting freight between public stations, basements and elevator shafts.</blockquote>
via <a href="http://www.urbanghostsmedia.com/2013/09/chicago-tunnel-company-underground-freight-railway-network-pictures/">Chicago's Historic Underground Freight Railway Network | Urban Ghosts |</a>.