Why do a lot of people claim Cherokee blood but never Blackfeet blood or even Navajo blood, why it's always Cherokee but never other tribes?

Romanticism, better documentation, longer trade ties with outsiders, and intermarriage. It’s lots of reasons… and often times it’s also a tale that’s false.

https://slate.com/news-and-politics/2015/10/cherokee-blood-why-do-so-many-americans-believe-they-have-cherokee-ancestry.html