Final answer:
Asian Americans were negatively affected by the Supreme Court's decision on Korematsu v. United States, which upheld the internment of Japanese Americans during World War II.
Step-by-step explanation:
The minority group negatively affected by the Supreme Court's decision on Korematsu v. United States was Asian Americans.
During World War II, Japanese Americans were subjected to internment camps due to the fear that they might be loyal to Japan. The Supreme Court, in its ruling on the Korematsu case, upheld the government's decision to intern all persons of Japanese ancestry, including both citizens and non-citizens, on the grounds of national security.
This decision contributed to institutionalized discrimination against US citizens based on their ethnicity, highlighting the challenges faced by Asian Americans during that time.