What about American Indian?

Okay that's simple enough. Indian-American is someone who legally emigrates from India to America. The American Indians are people who have always lived in the Americas.

"Native Americans" is the name given to those who lived in the Western Hemisphere on the North and South American continents, before its discovery by the Europeans."Middle American Indian" is a more...

Yes, you are considered 25% American Indian.

they gained citizenship with the Indian Citizen Act of 1924BUT WWI veterans were already granted citizenship in1919

you should call them native Americans because its more accurent to call them that also its more of a 5th grade word.