Is the history of the document automatically saved in the system?

Yes, we keep an audit log under "Redaction Log". It logs all redactions and shows you which user in your account made the redaction. This information is available on your Redaction Certificate, which you can choose to attach to your redacted document.  

We also store versions of your finalized documents. You can revert to previous versions. You can download previous versions. Each time you push the "Finalize Redactions" button, a new version is created.