@Cnewman The easiest way to view all tracks you have given a Thumbs Up to is to view your My Thumbs Up playlist.
My Thumbs Up is a playlist that collects your Thumbed-Up tracks from each of your stations. When you sign up for Pandora Premium, we begin it by adding your 1,000 most recent Thumbs (if you have that many). Moving forward, every time you Thumb Up a song on one of your stations or eligible playlists, it will be automatically added to My Thumbs Up.
Unlike Thumbprint Radio, which plays your Thumbed-Up tracks along with other you may like, My Thumbs Up playlists will only play the songs you have Thumbed-Up.
To view to this playlist, search for My Thumbs Up and sort by Playlists:
Please note that since you are currently using a free account, you will need to start a complimentary session in order to actually listen to the playlist. Clicking the play button will trigger a short advertisement, after which you can enjoy the playlist.
For complete control of what you hear on Pandora, try Pandora Premium. It combines our industry leading internet radio service with on-demand listening and easy playlist generation.
Hope this helps!