It's not hard to find sources about slavery in Asia.
"Slavery in Korea formally existed from antiquity up to the 20th century. Slavery was very important in medieval Korea; it was a major institution. [...] The Korean "nobi" system of slavery peaked between the 15th and 17th centuries and then declined in the 18th and 19th centuries." [1]
"The Mongol Empire (1206-1368) had a tremendous impact on slavery across Eurasia. While slaves played a minor role in pre-Imperial Mongolia, the Mongols saw people as a resource, to be distributed among the imperial family and used for imperial needs, like material goods. This view created a whole spectrum of dependency running from free men to full slaves." [2]
I'm not sure what you mean, but I don't think many countries still had legal slavery going into the 20th century, outside of the Arab peninsula.
In Korea it was officially abolished in 1894 (although it took a few decades to eradicate). In my own country, France, slavery was abolished in 1794 (in Europe) and in 1848 (in all colonies and oversea territories). I think it's the general timeline for western Europe, first half of the 19th century. So not exactly 20th or 21st century either.
Of course, slavery itself (especially related to prostitution) is still ongoing pretty much everywhere, but it's not legal. And then there's war: forced work (Germany and Japan during WWII), and arguably conscription could count as a form of slavery too...
I'm pretty sure I learned about it at school in France, although of course not each country individually. Not sure about your specific country and history curriculum.
It sounds like the authorities where you live should have a look at not just the history curriculum but the rest as well. Slavery is very much a contemporary issue and it's been around, globally, since times that predate written history.
also Inca and Aztechs were from south america right?
there is also a new form of slavery currently active in the US where immigrants are brought to work and their passports are kept with their "employer" until xyz condition.
so slavery still exists but it is no longer a government policy as it used to be in US
I don't understand how, in the 21st century can we have slaves or bonded labourers. Apalling
People now are the same as people then, just different fashions and widgets.
The 'new form' of slavery you're describing sounds like indentured servitude. Definitely not new to the US (though now illegal)! Benjamin Franklin was indentured for 2 years when he was a teenager to his older brother, and frankly was not a fan of the practice.
"Slavery in Korea formally existed from antiquity up to the 20th century. Slavery was very important in medieval Korea; it was a major institution. [...] The Korean "nobi" system of slavery peaked between the 15th and 17th centuries and then declined in the 18th and 19th centuries." [1]
"The Mongol Empire (1206-1368) had a tremendous impact on slavery across Eurasia. While slaves played a minor role in pre-Imperial Mongolia, the Mongols saw people as a resource, to be distributed among the imperial family and used for imperial needs, like material goods. This view created a whole spectrum of dependency running from free men to full slaves." [2]
[1] https://en.wikipedia.org/wiki/Slavery_in_Korea
[2] https://www.cambridge.org/core/books/abs/cambridge-world-his...