Chart 1. Fifteenth Census of the United States, Indian Population by States and Counties: 1930.

Notice that the title of this report is “The Indian Population of the United States and Alaska”: the Census of 1930 was the first in which Native Americans were counted as citizens of the United States (previously, they were counted as Indians living in the United States). Rather than being enumerated by a separate survey, Native Americans were counted in the census of the general population. A subset of questions collected information about tribal affiliation and native language.

Census book scan
Prepared under the supervision of Dr. Leon E. Truesdell, chief statistician for population Bureau of the Census.
Washington, D.C. : U.S. Government Printing Office, 1937.
Gould Library Government Documents