Others have stated Ecosia/Qwant building a European search index, but you also have Mwmbl with their own index that I believe is not American.
Additionally, you could also look at the various SearXNG instances hosted in Europe (or self-host your own!). They are meta search engines, meaning you can configure what sources and indexes they use for results and the ones you select are used together.
What is a fully US independent search engine?
Qwant
Not entirely, as currently, beside results from their own index, they also add search results from Bing.
Qwant and Ecosiaia are currently building a joint independent index
Yes, I know, that’s why I wrote “also”. I’ve edited my comment to make the point more clear.
Others have stated Ecosia/Qwant building a European search index, but you also have Mwmbl with their own index that I believe is not American.
Additionally, you could also look at the various SearXNG instances hosted in Europe (or self-host your own!). They are meta search engines, meaning you can configure what sources and indexes they use for results and the ones you select are used together.