Firefox stores your history and bookmarks together in a database file named places.sqlite which is in your profile folder. You may want to take a look at these articles:

• Profiles - Where Firefox stores your bookmarks, passwords and other user data
• Recover important data from an old profile

If I understand those articles correctly, they explain how to access that file from the Firefox application, but not from Time Machine. When I go onto Time Machine to restore from my most recent backup, where do I go to find the folder to restore from? Or do I simply have to entirely restore my computer from my most recent backup in order to get my browsing history back?

I don't know how to search in a Time Machine backup for a particular file. If you can't search by the file name places.sqlite, you could try looking in the backup for the same path that your current profile folder uses. One way to discover that path is to type or paste about:profiles in the address bar and press Return to load the list of profiles. Each profile shows its path on disk. If you have more than one profile, the current one is indicated by "This is the profile in use and it cannot be deleted."

If it doesn't work that way... maybe point Apple to the article and see if they can figure out where it is?

Edit: Sorry, about:profiles only has one colon between about and profiles.

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

https://addons.mozilla.org/en-US/firefox/addon/febe/ FEBE (Firefox Environment Backup Extension)

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.

https://addons.mozilla.org/en-US/firefox/addon/opie/ OPIE

Import/Export extension preferences

So, between these posts, and a visit to Apple's Genius Bar, I found a solution. (1) Access the Firefox profile folder as described above and click to have it open in Finder. (2) Close Firefox application. (3) While having the Firefox profile folder open in Finder, open Time Machine from the menu bar at the top of the Mac screen. (4) The Finder folder will then be displayed for all previous updates. Select the most recent update (or the update that would contain your browsing history), select the profile folder, and then click restore. (5) Exit Time Machine.

My Firefox browsing history is fully restored.

Thank you again for volunteering your time to help.

That was very good work. Well done. Please flag your last post as Solved Problem so others will know.