I have a large folder of edited images on Lightroom, but the (external) hard drive that I stored the original files on has been destroyed. I do not have a copy of the finished exported images from Lightroom. Lightroom has saved all of the edit history for each photo, but 'The file could not be found" is displayed at the top of each in the display. I do have backups of all of the original unedited images. Is there any way that I can apply the same history to a copy of the root file before having to redo all of the editing manually?
As long as the file names for the copies are the same as for the originals, you should be able to fix this easily.
Right click the folder in the folders panel, and point Lightroom to the folder containing the copies.
All the edits should now be applied to the copies.
I've never had to do this myself, but I think that's how it should be done.