Hey!
I think this might be the ticket. 

Archiving a lead list

Archiving hides a list from view while preserving all lead and interaction history for reporting. You can archive a list immediately, schedule an archive for later, or restore an archived list.

To archive a list immediately:

• Click the Edit icon next to the list.
• In the State dropdown, select Archived
• Click Save

To schedule an archive:

• Click the Edit icon next to the list.
• Check Schedule archive

• Select the date and time (displayed in your account’s time zone).

• Click Save

To un-archive a list:

• On the Campaign Loaded Lists page, select Archived from the State dropdown.
• Click the Edit icon, and choose your desired state.
• Click Save

But you can poke around this KB for a more holistic view on Managing Uploaded Lead Lists

Let me know if this hits the mark...and if not, we’ll take a deeper dive.