Speedometers on steam locomotives

A question has come up under Worldwide Railfan about speedometers on steam locomotives. In the U. S., about when did steam locomotives begin to be equipped with speedometers?

I don't know when speedometers/speed recorders were first put on steam engines.
However, when I worked for the New York Central I had the pleasure of taking
many cab rides in NYC diesels. Even though the engines were equipped with
good speedometer/speed recorders most of the "old head" engineers still used
their pocket watches and mile posts to time their speed. This was in the early
1960s.

And most engineers could tell speed just by listening to chugging.

That's sort of what I figured--"real engineers don't need speedometers." I wonder whether the ICC ever issued a regulation that any locomotives entering service after a certain date had to have a speedometer--or remaining in service after a certain date had to have one added.

pretty sure the ICC which pre-dated FRA , made rule to equip all engines with speedometers ,just like today with some of other mandates like PTC.

There were accurate ways of telling speed without speedometers. One old conductor said he used to count telegraph poles, while in the caboose, which had no speedometer. Since there was a fixed number per mile. So many seconds between poles could be used to calculate speed. The cadance of the rail joints was another method. Knowing the exhaust beats at the given valve cutoff was a pretty good indicator too. On diesels, after running a certain class, the engineer knows about how many amps load the engine makes at a given speed.

From the Dictionary of Terms in the 1925 Locomotive Cyclopedia:

"Speed Recorder. A device... placed in the cab for engineman's guidance. Required by law in some States."

Now there was only one example shown in the book, so I imagine in 1925 you could count on one hand the number of states requiring speedos.

I know that some railroads had a device on the engines to improve efficiency. It took the speed, and somehow mechanically gave the optimum valve setting.that the engineer should run.