If the change is the Industrial Revolution:
transcontinental railroad: helped to transport goods and get across the country
US army: helped to protect the US and make sure no one is going to break the new amendments
Discovery of resources in western land: Allowed the US to be able to expand and people would be able to live, could also give the US more money
Kangawaya. I’m not really sure how to spell it out it basically said that China had to hand over Hong Kong and open up its trading ports and allow the sale of opium.
The Cossacks is a group of Slavic people located between Ukraine and Russia that was created between the 14th and the 15th century by the emergence of 2 groups.
They played an important role in the 18th century during the Russian Empire, protecting its borders from Attacks, and participating in most of the wars.
They participated too in the Russian civil war in 1917, till they declared their independence in 1918.
We can still find Cossacks groups in Russia, Ukraine, United States, and of course other countries. They're considered as an ethnicity since 2010.
Hope this Helps! :)