The USGS web-site has a Cage's Ferry (historical) - (Why would you need a ferry if you had a ford? Maybe Mr. Cage offered choices.) in Sumner County. The citation is: Mergell, C.S. Military Map of Middle Tennessee and parts of Tennessee and Adjoining States. n.p., 1865.

A visit to the TopoZone site puts it right under a bridge crossing Old Hickory Lake due south of Gallatin.

Don't know if this helps or not.