Actually, they were not the first Americans.
While a minority of Indigenous people gained U.S. citizenship earlier through specific treaties, military service (such as in World War I), or individual naturalization, it wasn't until the Indian Citizenship Act of 1924 that Congress extended U.S. citizenship to all Native Americans born within the territorial limits of the United States.

Got it

Let’s see how fast this comment becomes low rated 😂

Only if they’re eye surgeons or dentists 😂