This is a relatively recent area of study for the fields of international development and development economics. The UN has a World Happiness Report and there are a number of institutions that are now trying to directly measure happiness as well as the usual well-being indicators (like health, education, freedom, wealth).
The data seems to show that improving those indicators seems to increase happiness up to a certain level, after which they have much more marginal effects. One theory is that once basic needs are met, happiness becomes "relative" to the people around you, so rich countries/societies getting richer doesn't further improve happiness.
I can't speak to what was going on 100 years ago but based on the above I'd imagine they were a lot less happy than we are now - as a lot of people were not having their basic needs met.
