The title of the 1890 photo above is “Four trains passing Little Falls.” That’s a town on the Mohawk River in upstate New York, about halfway between Utica and Amsterdam.1 The location tells us that this is the main line of the New York Central Railroad, but doesn’t answer the basic question of why would anyone care?
In 1890, most of the railroad lines in the US were single-track. 2 Since having trains running in both directions on a single track is bad, those lines had sidings to allow trains to pass one another, usually, but not always, at or near stations. Adding a second track more than doubles the capacity of the line. Adding two more tracks more than doubles it again. But only the heaviest-travelled lines could justify the expense of building and maintaining a four-track line, and only the wealthiest railroads could manage it.
In other words, this photo is showing off the wonder that was the NYCRR main line, where two passenger trains and two freight trains could run past one another.