American nationalism borne out at the juncture between empire making and immigration. At its core are constructed (and changing) ideas of race. Empire Making (building on long history: trans-Appalachian migration; the Louisiana Purchase, Indian Removal, Manifest Destiny, the Mexican War, and he annexations of Texas, California, and the southwestern territories), Philippines, Cuba, Guam, Hawaii (Spanish-American War)
Nationalism as a natural product of imperialism? Or... Imperialism is a natural product of nationalism? Each reinforces the other. As Jacobson's work shows, the ideas of "American-ness" developed at the juncture of migration, racism, and empire building.