I neglected to say that simply draging the lock icon from the Background layer to the trash will convert a Background to a layer - Thanks to Jeff Tranberry for that additional shortcut!
Double clicking on the “Background” layer in the Layers panel will display the New Layer dialog box - changing the Background into a layer and giving you options such as the ability to rename the layer. Option (Mac) / Alt (Win) -double clicking on the “Background” will change the “Background" into a layer - bypassing the dialog box. If you choose the second option, and then need to rename the layer at a later time, simply double click the layer’s name in the Layers panel to rename it.