Yes that's what people think instinctively but it's incorrect. Part of the issue is that two world wars served to erase tremendous amounts of the visible cultural legacy of the German influence on the US, streets and towns were renamed, biergardens turned into bars, and so on.
The culinary influence is right there in plain sight though if you look for it, from the names of our big mainstream brewing companies to our national favorites, the Frankfurter and the Hamburger.
Interesting. I was just reading about Texas barbecue a couple of days ago (in fact I have a few tabs about cuisines open in my browser right now). They said the influence was from Germans, as you said, also Czech, IIRC (for the barbecue). Apparently East, Central, West and maybe South Texas all have different styles of barbecue.
Maybe I'm slow, but I've sometimes idly wondered why Hamburgers contain no Ham - and your comment finally made be twig: it's Hamburger as in /ˈhambɜːrɡər/ not /ˈhæmbɜːrɡər/ !
The culinary influence is right there in plain sight though if you look for it, from the names of our big mainstream brewing companies to our national favorites, the Frankfurter and the Hamburger.