There are many obvious English food influences found in America, such as the Sunday roast beef (Yankee pot roast). Remember though that Germany was a larger source of immigrants than England from 1820 until WW I. Even today, the 46 million Americans of German-descent constitute the largest single ethnic group in the US (unless you count Hispanics together, regardless of country of origin). The majority of the German immigrants were farmers or working-class. Many turned to street-vending, marketing and the food trade, bringing their imported recipes along with the rest of German culture: beer, (Budweiser beer founded in St. Louis in 1876), chicken-fried steak, hamburg steak, frankfurters and bratwurst, along with Christmas trees, gingerbread houses and the Easter Bunny (Osterhase). Someone may also want to weigh in the contributions of the Pennsylvania Dutch.

Anti-German sentiment rose to a hysterical pitch during WW I however — German immigrants had to carry identity cards; some 4,000 were interned — leading to the rebranding of all things German. Germans begin to overtly assimilate. Whereas English dishes (like roast beef, trifle, spotted dick) remain identifiably English, German menu items face revision or translation. A hamburg steak^1 becomes a Salisbury steak, a frankfurter becomes a liberty sausage^2 for a while (at least until the term hot dog catches on). The latter case is strikingly similar to the House of Representatives rewording their cafeteria menus to replace french fries with Freedom Fries in a fit of patriotic rebuke to France's opposition to the US invasion of Iraq.

tl;dr Germany was the largest source of immigrants to the US for much of the 19th century. Anti-German sentiment in the US during and after WW I, however, leads to a concerted effort to rebrand, co-opt and assimilate German food culture.

^1 A hamburg steak is chopped beef, mixed with onion and egg (possibly milk), cooked, generally attributed to the city of Hamburg, although variants of raw or cooked, minced beef dishes are widespread. There are several historical and local claims to having originated the hamburger on a bun, including one for the Erie Fair in Hamburg, New York in 1885, but it seems likely that the idea of serving a hamburg steak on bread was simultaneously hit upon by numerous American street and fair vendors.

^2 edit: forgot to mention the poor German dachshund, shunned and despised, despite being recast as "liberty puppies".