That shows first that the wave that overwhelmed the US came from Europe, meaning that the limitations on Chinese travelers were only minimally helpful if that; and second, that politics played a huge role in the spread of the disease.
Namely, after the initial surge around NYC, the epicenter switched to the deep-red south and then moved up the midwestern corridor. In short, the pandemic followed the lead of politicians who denounced masks and refused to enforce shelter-in-place plans.
Not totally. It was porous, to be sure, letting tens of thousands of people in from China. But as the map shows, very few of those people were infected.
The vast majority of the infections in the US came from Europe, particularly Italy and France. When the administration imposed another (porous) ban on travelers from Europe, it was too late.
But hey, if you refuse to adopt a national mask and distancing regimen you can transform the US into a hothouse from which the rest of the world is seeded. Let no one ever question America's willingness to share with other countries.
Notice that New Mexico has consistently been among the lower groups of contagion.
Our Governor has been very strict, locking things down, keeping a tight grip on what can be done and what can't, insisting on masks and levying fines on people who won't wear them. Every once in a while you hear somebody whine that they can't wear a mask "for medical reasons." I wish the Gov would make hem get written proof of this, along with the reason WHY, from their doctors. I have read any number of doctors' reports that say there are VERY few people (aside from infants) who genuinely should not wear masks.
Many of our businesses here - including big-box stores - have signs in the windows making it VERY clear that NO ONE is allowed to enter the building without a mask. Most of them also offer to let you give your shopping list and credit card to a store employee who will do your shopping for you if you cannot enter the store with a mask on, and deliver the goods back to you with the receipt when the shopping is done. (From what I've seen, very few people will take advantage of that. They will don their masks, with a great deal of grousing, and do their shopping.) They just don't like to be told what to do.
When I remember the old newsreels of England during the Blitzes of WWII, when people had to keep their lights out at night, put up with being rousted out of their homes at any hour and herded into bomb shelters, etc. - you don't hear a lot about people asserting their "rights" to remain exposed to the danger. What a difference in mentality.
I think a lot of it can be traced right back to the "leadership" (or lack thereof) demonstrated in the White House.