Conversation so far:
Where was William Henry Dietz from?
According to his birth certificate, William Henry Dietz was born William Henry Dietz, or Willie, on August 17, 1884, in Rice Lake, Wisconsin, at 16 West Humbird Street.
Where did William Henry Dietz attend school?
Willie attended Oklahoma's Chilocco Indian Agricultural School.

Question: In what year did he go there
Self-contained rewrite: In what year did William Henry Dietz go to Oklahoma's Chilocco Indian Agricultural School?