Final answer:
The loss of jobs and homes is a detail that serves as evidence that internment harmed Japanese Americans.
Step-by-step explanation:
One detail that serves as evidence that internment harmed Japanese Americans is the loss of their jobs and homes. According to the excerpt, under Roosevelt's order, both immigrants and American citizens of Japanese descent were rounded up and placed in prison camps, resulting in the displacement of thousands. This loss of livelihood and stability would have had a significant impact on the lives of Japanese Americans.