[cmehdy]

Not to mention that from 1800 to 1930 the world population doubled (1 billion to 2 billion, passing the 1.5 mark just around 1900).

While this pales in comparison with the 6 billion humans added since, that's a significant change - particularly for most likely available recorded sources - at a time of monstrous evolutions to major world powers/empires, expansion into vast new areas of the world (namely North America) of essentially the British empire (while at the same time the East India Company ceased to exist by the end of the century for contrast), some abolition of slavery becoming a reality in places (1833 for the British), and what arguably kickstarted much of the mental frameworks for our entire lives: the first two industrial revolutions (for example: democratization of once-monastic school system while adopting the year-of-production type of mental model for its promotions).

1804 is the first locomotive. 1859 is The Origin of Species by Darwin. 1861 is Maxwell equations. 1869 is Mendeleev's period table. And so on and so forth[0]. Measurement devices also improve in reliability and efficiency, leading to many of the early recordings we can now look back at when it comes to the consequences of the explosion of human activity with regards to the environment.

It's quite a fantastic century to keep a trace of, frankly.

[0] https://en.wikipedia.org/wiki/19th_century#Science_and_techn...