I usually advise Americans to NOT broadcast that fact by logos, flag, or patches on rucksacks, hats, t-shirts, etc. US brands / logo are fine as they are sold globally. But, and by way of an acute example, wearing a red MAGA ball cap, or items of military type gear is NOT a good idea at present. Wearing anything that screams "I am an American" could attract unwanted attention.
The reason is simple. In many countries, access to all sides of news and information on issues is not as dynamic as it is in North America. As a consequence, there are many folks you will meet who are fine people and nice to be with in their own right. But, not everyone necessarily likes America or Americans. To each his or her own...
In my experience, if some folks find out too soon that you are an American, you could become their lightning rod for all things they dislike about America, writ large. You might become their 'scapegoat' or 'whipping boy' just because you are there. It has happened to me many times over decades of travel. This is not limited to the Camino. I can deal with it. Not everyone can.
Please do not be put off by this. Also, I am not making categorical statements intended to slam any person or place. This post SHOULD NOT be intended as having a political subtext.
I am just suggesting that you take it slow, and go with the flow, until you know people well enough. You will meet many people from all over the world. The key to getting on with everyone you meet is to deal with them through the context of the Camino.
We all share that affinity and common goal. We are all pilgrims... Differences in race, religion, place of birth, etc. are much less important than you might realize when on Camino.
I have made many acquaintances and friends over a glass of cerveza or vino, that I might not have otherwise have met or engaged with, if not for the Camino. You just need to avoid subjects that are touchy and concentrate on those areas of shared interest. Over the years, I have learned to LOVE Spanish futbol (soccer), especially during the summer tournaments.
In my wanderings, I always try to take each person I meet as an opportunity to show them that I am a person just as they are. I am a global citizen, I am also a pilgrim, then I am an American. I am proud of my nationality. I just do not broadcast it for all to see, first.
I sincerely hope this helps the dialog.