Some electrified intercity railroads in the Northeast used 25 Hz power. There are, or at least were in the past, some advantages to 25 Hz power for running locomotives. (Some railroads in other parts of the world use or used 16-2/3 HZ power.
This same flicker was apparent when I stayed with my parents at the Fred Harvey Hotel at the Santa Fe Railroad stati> Note that for many years DC power was provided by commercial
Most of today's power companies descended from Edison's companies and are still reluctant to give any credit to Nikola Tesla, who conceived of the far more practical (for most commercial purposes) multiphase alternating current now universally used. (Westinghouse bought the Tesla patents.)
Wes Leatherock email@example.com firstname.lastname@example.org