Was president roosevelt justified in ordering executive order 9066, which resulted in the internment of japanese american citizens? it's an essay btw.

This is a matter of opinion.
If you think yes, you could argue that internment was a great PR move and/or that it protected the Japanese living in America from negative press
If you argue no (which I would) then you could argue that it was unconstitutional and/or had no strategic importance to the war itself.

Answer is mass marketing.