Make sure you do not run Firefox in Full Screen mode (press F11 or Fn + F11 to toggle; Mac: Command+Shift+F).

• https://support.mozilla.org/en-US/kb/how-to-use-full-screen

When you are in Full Screen mode, hover the mouse to the top of the screen to make the Navigation Toolbar and Tab bar appear. You can use one of these to leave Full Screen mode:

• press the F11 key
• click the Maximize button at the right end of the Tab bar
• click the Full Screen button in the "3-bar" Firefox menu button drop-down list
• right-click empty space on a toolbar and click "Exit Full Screen Mode"

Somehow I managed to open another window and THAT one had the tool bar, so I closed the original window. Problem solved. Not sure what I did to cause it but it sure was frustrating. Thanks so much for your directions. I've printed and saved them.

This can happen if you have opened a pop-up window that disabled some items in a tab. You can prevent websites from disabling specific features by setting dom.disable_window_open_feature prefs to true on the about:config page.

• http://kb.mozillazine.org/Prevent_websites_from_disabling_new_window_features

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

• http://kb.mozillazine.org/about:config