Hi!
Following is the query executed when the request status link is selected:
select user_id as modified_by, status_date as timestamp, status
from usm_request_status
where request_id = <request id> and subscription_detail_id is NULL
order by request_status_id asc
The status value correlates to the associated string within %USM_HOME%\view\webapps\usm\locale\icusen\request\requestshared.xml which is displayed in the UI (i.e. Approval Done).
Thanks,
Jason