What was John Morris most famous poem?

There is no famous poet named "John Morris". It's possible you're thinking of someone else, or there might be a misunderstanding.

To help me find the poet you're thinking of, could you provide any more information? For example:

* What kind of poetry did they write? (e.g., romantic, nature, war)

* What time period were they from? (e.g., 18th century, 20th century)

* Is there any other information you remember about them? (e.g., a specific poem title, their nationality)

With more details, I can help you find the poet you're looking for.