How to Get Back Deleted History?
Using Fx version 48.0.2.
Under Tools/Options/Privacy/History I had "Clear history when Firefox closes" and forgot I checked under Settings/When I quit Firefox, it should automatically clear all:/Browsing & Download History.
Is there anyway to recover all the lost History?
Opaite Mbohovái (2)
To protect user privacy, when Firefox deletes your history it isn't possible to restore this deleted data. Sorry about that.
These can't get your data back, but will help in the future.
These add-ons can be a great help by backing up and restoring Firefox
FEBE (Firefox Environment Backup Extension) {web link} FEBE allows you to quickly and easily backup your Firefox extensions, history, passwords, and more. In fact, it goes beyond just backing up -- It will actually rebuild your saved files individually into installable .xpi files. It will also make backups of files that you choose.
OPIE {web link} Import/Export extension preferences