What primary advantage does globalization offer the people of developed nations

developed countries can produce their products in other (usually underdeveloped) countries where the labour is much cheaper. For them it is much more effective capitalism. Another advantage is that they can (quite easily) extract and later use raw materials in these underdeveloped countries (usually not able to extract and use their own raw materials).

Explanation: Parts of the population of the underdeveloped world (so-called Third world) feels this is unjust. These people usually use word (which in fact belongs to late 19th and early 20th century) "imperialism".

because it took place after the war of 1812 had come to an end.