German American-ness is pretty interesting because it is still widely reported and recognized as an ancestry but it stopped being a distinct sociopolitical identity a long time ago. It could be argued that German American culture not only assimilated into generic middle American culture but effectively came to dominate it, especially in food (after barbecue, what image does "real American food" conjure in the rest of the world if not hamburgers, hot dogs and lager beers with names like Budweiser?).
Part of that decline in German-American “distinctiveness”—not all of it, but certainly part of it—was the impact of the World Wars. Much more of an incentive to assimilate!