Next two chapters in Myth America are on Native Americans, by Ari Kelman, and Emigration, by Erika Lee.
The first seems loosely focused around that idea that Native Americans aren't "vanishing", as Dee Brown and the recently retired ad would say. The second is mostly about the nativism with which those who lived in the US greeted arriving immigrants, sometimes barring entry to groups or limiting numbers.
I have a problem with this sentence: "The United States has been a particularly powerful actor shaping the movement of peoples by causing human displacement through war and foreign and economic policies.." The author does not support this assertion; indeed she doesn't discuss it at all that I see. The problem is it's not true for most of our history, at least as far as war goes. Immigrants have come from Germany, Italy, Philippines, Korea, Japan, China, and Vietnam--all countries where we've fought wars. But in all the cases the immigration was either the movement of the losers to their supporter (i.e, Vietnamese, Hmong, Chinese) or movement because the war and subsequent occupation troops established pathways for the movement.
Coincidentally the NYTimes has an article today discussing another immigration myth, that immigrants come and stay. In fact through much of our history many immigrants have left. That continues today. The pattern described in the article seems to be: come to US and work for the money; return to the homeland for family and retirement. Prof. Lee does not mention this, though the fact of immigrants leaving undermine the myth that America is so great no one would leave once here;