How does Victoria 2 attract domestic immigrants?

Deep reform. Victoria 2 is a large-scale strategy game set in the colonial period of19th century. Players need to control the whole country and guide the country's industrialization, political reform, military occupation and colonization. In the game, only in-depth reform can attract domestic immigrants. Players need to bring the policy of "Destiny by Heaven" to the United States, so that Britain can become a powerful empire in the world and Germany can occupy a dominant position in Europe.