The time span that the Victoria games cover, has to be one of the most xenophobic periods in human history. People of different cultures, ethnicity and races were neglected and sometimes even barred entry into a country, due to their heritage. Countries with strict nativist laws and immigration such as the US, blocked countless desperate people from entering the nation, with backgrounds as varied as African to Irish to Chinese to Polish. Western nations geared their laws to preserve what they called "ethnic purity", so its no surprise that immigration played a very important and vital role during this period. All of this considered, it comes to me as a surprise that immigration laws and policy were somewhat neglected and shallow in the Victoria 2 game, which is strange when you take into account how much immigration mattered for the Americas, Australia, South Africa and so on. I think a lot of this could be remedied with an immigration quota system, that would allow you to bar certain ethnic and cultural groups from entry into the country. Yes, having the ability to finally create an ethnically pure Zulu/Russian mixed nation would be kinda cool, and would also more accurately represent the times. I think that having a quota system where you can set preferences for certain ethnicities or countries should look like the image below, where the more bars you put towards a nation, the higher your chance will be of getting only their immigrants, while putting no bars towards a nation, blocks their immigrants from getting in entirely. Having this in Victoria 3 would be amazing, but it would also be cool to mod this into Victoria 2.