Why was there no 'Indian schedule' in the 1920 census?

Question

Hello 
 I understand that there was a special 'Indian schedule' used to enumerate Native Americans for the 1900 and 1910 census, but that this schedule was discontinued from the 1920 census onwards. Among other things, this led to a undercount of the Native American population in 1920. 
 I was wondering if there was any known reason for this change (e.g., in order to reduce costs, or because of a change in priorities at the Census Bureau). I was not able to find any reference to the change in the Act of 1919 ( https://www2.census.gov/programs-surveys/decennial/1920/1919-census-act.pdf ), nor in various overviews of the 1920 census (e.g., https://www.census.gov/history/www/through_the_decades/index_of_questions/1920_1.html ). 
 Thank you for your time.

A1 Reference Branch · Answer

christian_maruthiah 
 Thank you for posting your question on History Hub! 
 We did a quick search in our finding aids, and were unable to locate a series that explicitly discusses this issue. However, we highly recommend that you contact our unit at archives1reference@nara.gov , as it is possible there may be information relevant to your topic in a series that is not fully described (for example, "General Correspondence" or the like). 
 We hope this assists you with your research! 
 Sincerely, Archives 1 Reference Branch (RR1R) RR1R-24-16593-KV

jhagan5216 · Answer

By 1920, the US government had reclaimed all the unclaimed Indian land; they had had the land grab run; and Oklahoma had become a state, and was no longer considered Indian Territory. The Dawes Rolls were closed. 
 President Grover Cleveland felt the best way to take care of Indians was to make them part of white society. So there would no longer have been any need for a separate Indian Schedule on the census. 
 At least, that would be my best guesstimate in going thru records.