Blockquote not working (problem resolved)

This is a brief how-to, to hopefully help others in the same situation.

When I quoted a message as a regular member user, the quote was not appearing in a blockquote. The problem was that I did not have the blockquote CKEditor element enabled in the toolbar for that text format being used by the user. Once I added that button to the toolbar by editing the chosen format at /admin/config/content/formats, the subsequent quoted messages began appearing in blockquotes.