The answer is "somewhere between, but growing toward more widespread consumption." Pasta was, rather famously, served in the US in the Jefferson white house, and in fact Thomas Jefferson had a diagram for a pasta-making machine that he would eventually have shipped to the US (but, interestingly, he'd order pasta from Europe), and a recipe for maccaroni and cheese, with a notation on making pasta and adding it to soups, too.

On the other end, after WWII, there are a number of GIs who spent time in Italy and came back to the US with something of a thing for pasta. Though the origins are not certain, a leading theory is that pasta carbonara was created by GIs in italy.

Going back in time from the 1940s, there is significant Italian immigration to the US, and the Italians brought a lot of their food traditions with them. Though I have not seen numbers on regional pasta consumption, I can assure you that it would follow, in large part, immigration patterns. Pasta was not considered a particularly fancy food though, probably because Italian immigrants did not bring with them a lot of (a) money or (b) cultural cachet.

Let's look at cookbooks. Fannie Farmer (1912), among 860 recipes, has three for maccaroni and two for spaghetti, one of which is "Napoli Spaghetti." The Delmonico cookbook (1890) has more recipes for pasta / spaghetti, and but has more recipes overall too. The ratio is about the same. Ironically, pasta was something of a luxury item in Italy, but less so in the U.S.

I have looked, but not immediately found, import / production / consumption numbers over the last 100 years for pasta. Korby Kummer pegs the numbers at 3.75 pounds per person per year by the end of the 1920s and negligible before that, but he doesn't cite a source.