Why did Americans make a difference between the nisei and issei?

Americans differentiated between nisei (second-generation Japanese Americans) and issei (first-generation immigrants) primarily due to their citizenship status and cultural assimilation. Nisei, born in the U.S., were American citizens and often seen as more integrated into American society, while issei, being immigrants, were viewed with suspicion and often faced discrimination. This distinction became particularly pronounced during World War II, when nisei were sometimes treated more favorably than issei, despite both groups facing prejudice and internment. Ultimately, these differences reflected broader attitudes toward Immigration, citizenship, and identity in America.