Final answer:
The primary reason for passing various Immigration Acts in U.S. history was influenced by nativism and economic concerns, such as job competition and maintaining 'American homogeneity.' The laws intended to limit immigrants from certain regions according to the prevailing attitudes of the time, with shifts in policy reflecting changing societal concerns.
Step-by-step explanation:
A primary reason the Immigration Act was passed was nativism, which is an ideology or policy favoring native inhabitants over immigrants. This sentiment was intensified by economic concerns such as job competition and the desire to preserve "American homogeneity." Throughout U.S. history, different Immigration Acts were influenced by nativist attitudes and the economic context of the time, with varying impacts on immigration policies.
For instance, the Emergency Quota Law of 1921 and the National Origins Act of 1924 both reflected these nativist sentiments, limiting the number of immigrants mainly from Southern and Eastern Europe, as well as Asia, aligning with the isolationist trends of the era. These laws were intended to maintain the cultural and ethnic composition of the country as it was in earlier decades, particularly favoring northern and western European immigrants.
Likewise, the Immigration Act of 1965 sought to eliminate the prejudiced quota system of the past, emphasizing family reunification and skills-based immigration, which led to the diversification of immigrant populations from Asia and Latin America. Over time, concerns over illegal immigration and societal integration led to acts containing provisions such as the one in 2006 which was to declare English as the national language, demonstrating the ongoing influence of nativist thought on immigration reform.