I have created a custom currency field, in Salesforce, on the standard Opportunity object. It's not a formula field; a workflow updates this field on edit/new opportunity. I have enabled Field History tracking on this field.
I want to include this field on a trend report with 2 snapshots of the field's value. The issue is that I don't see the field's historic value available to be selected under the "Opportunity (Historical)" field list. So, it seems like the value has not been added to this related object. (I can see the other standard fields' snapshot values.)
I went to the Report Type to see if I could add it there, but again, it's not available to be selected; only the field that's in the actual opportunity is selectable.
What steps have I missed?