Answer:
Yes, nationalism has always been a "thing" in the United States, and is still today. There are several examples of this.
Step-by-step explanation:
One of these examples is the promotion of economic protectionism justified by nationalist arguments. Economic measures like tariffs or import quotas, which have been implemened in the U.S. in recent years, are seen by most economists as economically harmful for the majority of people.
However, these measures still enjoy a lot of popularity not only because they do benefit sections of people, but also because of the nationalist sentiment of having a good produced within the country. This is therefore, a form of economic nationalism.