When you start typing in Firefox's Location bar, a drop-down list of pages from your history and bookmarks that match what you've typed will be shown. For more information on the autocomplete feature of the Location bar, also known as the "Awesome Bar", see the Awesome Bar - Find your bookmarks, history and tabs when you type in the address bar article.

Why clearing history does not clear the Location bar

Items that appear with a star along the right edge are part of your bookmarks and not your browsing history.

Removing bookmarks results from the list

1. At the top of the Firefox window, click on the Firefox button and then select OptionsAt the top of the Firefox window, click on the Tools menu and then select OptionsOn the menu bar, click on the Firefox menu and select Preferences...At the top of the Firefox window, click on the Edit menu and select Preferences
2. Select the Privacy panel.
   
   
3. Beside When using the location bar, suggest, set the drop-down menu to either History or Nothing.
   • History will make the Location bar autocomplete list only display results found in your browsing history, not bookmarks.
   • Nothing will turn off autocomplete.
4. Click OK to close the Options windowClick Close to close the Preferences windowClose the Preferences window .