Excellent question; we often hear that "life was better before" and that "back in the day when there was a single bread winner, things were awesome." I contend that this presumption is a little off. To answer it we must look at the demographics of a country to get an answer. Let's look at the USA at 1900:
The 1900 census reported that the US had 60 % of its population living in rural circumstances. 60% of the population lived on the land! That implies that the largest segment of the US population engaged in farming, not wage labor. And can you visualize a housewife on a family farm just hanging out at home and reading magazines and gossiping? No way! Everyone was working their buts off the whole summer, including women and children.
So to answer your question, no in 1900 there was not a single wage earner in a typical family. There were zero wage earners and plenty of work to do.
After the industrial revolution, some farming families would send their teenage daughters to work in factory towns to be wage earners. One example of this is from 60 years earlier in Lowell. These girls traveled from their farms to Lowell, worked for 3 or 4 years and lived in company dorms. They had no spending money, as their wages was sent back to their families. This "teenage girls go to the city" stuff is still happening, if you watch China Blue you can see it in modern form. Another example I know of relates to Japan between 1870 and 1910. Silk export constituted the bulk of foreign exchange earnings that were used to modernize Japan. And the silk was processed through the underpaid labor of young Japanese women working in silk factories. They worked for years dipping their hands into boiling water to grab silkworm cocoons.
We can dig further and find more examples, but my point is obvious: In both rural and urban situations in the past, most women worked very hard for survival just like men. (Likewise, single working mothers were not rare either; disease and war were still overly common)
But why on earth do we always hear about the good old days of when Women were expected to just be housewives, and they "had to have dinner ready by the time hubby gets home from the office" and they "had to make sure to wear heels and pearls so that he is happy". We hear about this so much, but in 1900 and before, it obviously wasn't so. Where does this meme of the eternal housewife come from?
I don't have a source for this, but the concept of "working husband with a stay-at-home housewife" is a middle class / upper middle class "value" that started in the 1800 as the growing middle class sought to imitate the behavior of royalty. Supposedly in the post WWII US economy, aided by the GI Bill, most Americans became "middle class in the late 1940s and 1950s. So I think a good assumption is that the concept of "most families" having "stay at home wives" began in the 1950s.
However, I haven't seen any demographics proving this. I know both my grandmothers worked in the 50's and 60's once my parents were in school. From this anecdotal evidence, I assume that at no time in history did most families in the USA have "stay-at-home" women.
I'll make another assumption: Today, upper-middle-class women have the luxury of choice to be housewives. They might live in large suburban houses, while their partner earns a fortune doing something. These people existed in 1900 as well. However, the women today in these well-to-do situations can have a career, while in the 1900's women in this social class were expected not to work in anything except charity. Unfortunately, this wealthy class did not, and does not constitute "most people".