Analysis of information sources in references of the Wikipedia article "List of tram systems by gauge and electrification" in English language version.
Worst of all, not all city systems were built to the standard American and European gauge of 4'-81⁄2". Pittsburgh and most other Pennsylvania cities used 5'-21⁄2", which became known as the Pennsylvania trolley gauge. Cincinnati used 5'-21⁄2", Philadelphia 5'-21⁄4", Columbus 5'-2", Altoona 5'-3", Louisville and Camden 5'-0", Canton and Pueblo 4'-0", Denver, Tacoma, and Los Angeles 3'-6", Toronto an odd 4'-107⁄8", and Baltimore a vast 5'-41⁄2".
