The catalogs must still be on your system. It seems unlikely you would go into the catalog folder and delete them. Try using spotlight to search your system for files ending .lrcat
Control-click on each to launch.
It's best to set prefs to backup the catalog every time you quit the LR application
I didn't go into the catalog folders and delete.....On one press of a button, I deleted everything including all folder structure's, everything. I was being helped by a web-designer and we were trying to put my old system onto my new comp, to access some of my old images..... I don't know what happened but it would appear i eradicated my whole system. I was able to retrieve the system by restoring all data through the Feb back-up. I was also able to get back certain files, like my mail......from feb on. But trying to get back any work done on lightroom, well it just does not seem to be there. I feel this could just be a very expensive mistake. Any other thoughts?
Sorry I can’t think of anything else unless you happen to discover something more recent from Time Machine.