The official WRA record from 1946 states it was 120,000 people. See War Relocation Authority (1946). The Evacuated People: A Quantitative Study. p. 8.. Japanese Americans that were 1/16th or less were excluded from being sent to the camps but above that was considered a threat to the United States. This number does not include people held in other camps such as those which were run by the DoJ or the Army. Other sources may give numbers which are slightly more or less than 120,000.
doi.org
Everett Marko, David (2019). "Nevertheless, They Persist: American and European Muslim Immigrants in the Era of Trump". Journal of Muslim Minority Affairs. 39 (2): 246–258. doi:10.1080/13602004.2019.1620006. S2CID195563923.
Piazza, James; Van Doren, Natalia (2023). "It's About Hate: Approval of Donald Trump, Racism, Xenophobia and Support for Political Violence". American Politics Research. 51 (3): 299–314. doi:10.1177/1532673X221131561. S2CID252774439.
Everett Marko, David (2019). "Nevertheless, They Persist: American and European Muslim Immigrants in the Era of Trump". Journal of Muslim Minority Affairs. 39 (2): 246–258. doi:10.1080/13602004.2019.1620006. S2CID195563923.
Piazza, James; Van Doren, Natalia (2023). "It's About Hate: Approval of Donald Trump, Racism, Xenophobia and Support for Political Violence". American Politics Research. 51 (3): 299–314. doi:10.1177/1532673X221131561. S2CID252774439.