Nisei in the context of "G.I. generation"

During World War II, the United States forcibly relocated and incarcerated about 120,000 people of Japanese descent in ten concentration camps operated by the War Relocation Authority (WRA), mostly in the western interior of the country. About two-thirds were U.S. citizens. These actions were initiated by Executive Order 9066, issued by President Franklin D. Roosevelt on February 19, 1942, following Imperial Japan's attack on Pearl Harbor on December 7, 1941. About 127,000 Japanese Americans then lived in the continental U.S., of which about 112,000 lived on the West Coast. About 80,000 were Nisei ('second generation'; American-born Japanese with U.S. citizenship) and Sansei ('third generation', the children of Nisei). The rest were Issei ('first generation') immigrants born in Japan, who were ineligible for citizenship. In Hawaii, where more than 150,000 Japanese Americans comprised more than one-third of the territory's population, only 1,200 to 1,800 were incarcerated.

Internment was intended to mitigate a security risk which Japanese Americans were believed to pose. The scale of the incarceration in proportion to the size of the Japanese American population far surpassed similar measures undertaken against German and Italian Americans who numbered in the millions and of whom some thousands were interned, most of these non-citizens. Following the executive order, the entire West Coast was designated a military exclusion area, and all Japanese Americans living there were taken to assembly centers before being sent to concentration camps in California, Arizona, Wyoming, Colorado, Utah, Idaho, and Arkansas. Similar actions were taken against individuals of Japanese descent in Canada. Internees were prohibited from taking more than they could carry into the camps, and many were forced to sell some or all of their property, including their homes and businesses. At the camps, which were surrounded by barbed wire fences and patrolled by armed guards, internees often lived in overcrowded barracks with minimal furnishing.

Sansei (三世, "third generation") is a Japanese and North American English term used in parts of the world (mainly in South America and North America) to refer to the children of children born to ethnically Japanese emigrants (Issei) in a new country of residence, outside of Japan. The nisei are considered the second generation, while grandchildren of the Japanese-born emigrants are called Sansei. The fourth generation is referred to as yonsei. The children of at least one nisei parent are called Sansei; they are usually the first generation of whom a high percentage are mixed-race, given that their parents were (usually), themselves, born and raised in America.

The character and uniqueness of the sansei is recognized in its social history.

Issei (一世, "first generation") are Japanese immigrants to countries in North America and South America. The term is used mostly by ethnic Japanese. Issei are born in Japan; their children born in the new country are nisei (ni, "two", plus sei, "generation"); and their grandchildren are sansei (san, "three", plus sei, "generation").

The character and uniqueness of the issei is recognized in their social history.