Cheyenne State Leader for September 3, 1916. The Eight Hour Day becomes law.

This is an interesting 1916 item to say the least.  The moment at which the eight hour day became the American standard.

We're so used to thinking of the average working day lasting eight hours that we hardly give any thought to there being an error in which this wasn't the case. But there certainly was.  Prior to 1916, many laborers worked well over eight hours pre day. After September 3, 1916, that work day was established and the modern work day became law.

Which is not to say that there  hasn't been some retreat on this. There certainly has.  At least for the "professional" class of worker the eight hour day has long ago expanded into more hours than that, and well over forty hours per week. As more and more Americans have entered this category, the working hours of American have been increasing in recent decades, with wages not doing the same.