Early railroads pre-1870 named almost all their engines. The Philadephia & Reading had hundreds of “gunboat” class 4-6-0’s that were named for Civil War gunboats. Switchers were named for small mammals (Mink, Fox, Wharf Rat, Ermine, etc). One of the “Golden Spike” engines was the Jupiter.
When train orders became common, engine names went away. They didn’t work as well.
Extra Antiedem Creek West meet No 405 Eng Pittsburgh at Lenape
vs.
Extra 346 West meet No 405 Eng 207 at Lenape
I seem to recall that the Virginia and Truckee used both names AND numbers on their early locos.
OTOH, the Richmond, Fredericsburg and Potomac named (as well as numbered) their last 4-8-4 locomotives - after famous Virginia governors, generals and statesmen.
Innumerable early short lines had a Number 1 - and were never long-lived or prosperous enough to acquire a Number 2.
Chuck (Modeling Central Japan in September, 1964 - where locomotive numbers were alpha-numeric and included the class.designator)