An interesting point being made by the economic historian, Brad Delong :
To put it another way: In 1870 the daily wages of an unskilled worker in London would have bought him (not her: women were paid less) about 5,000 calories worth of human, not horse food: not oats (although Scotsmen would disagree) but bread--5,000 wheat calories, about 2½ times what you need to live (if you are willing to have your teeth fall out and your nutritionist glower at you). In 1800 the daily wages would have bought him about 3,500 calories, and in 1600 2,500 calories. Karl Marx in 1850 was dumbfounded at the pace of the economic transition he saw around him. That was the transition that carried wages from 3500 calories per day-equivalent in 1800 to 5000 in 1870. Continue that for another two seventy-year periods, and we would today be at 10,000 calories per unskilled worker in the North Atlantic today per day. Today the daily wages of an unskilled worker in London would buy him or her 2,400,000 wheat human-food--potato--calories. Not 10,000. 2,400,000. That is the most important fact to grasp about the world economy of 1870. The economy then belonged, even for the richest countries, much more to its past of the Middle Ages than to its future of--well, of you reading this.
It's also worth noting that from Angus Maddison's figures GDP per capita in England in 1870 was about $3,200 (yes, of course, in inflation adjusted dollars). The living standard of roughly India or Nicaragua  today.
It's a reminder of quite how poor our forefathers were: or how rich we are if you prefer. And also of quite how poor some other places still are. Along with, of course, the point that to get those other places rich, as we all should want to happen, is going to mean those other places following the same sort of economic path as we did. That strange mixture of capitalism and markets that propelled that North Atlantic world into unprecedented prosperity.