Today, as your persona write a letter to a friend.
If your persona is a fictional character, you can make up the friend, right? But if your persona is real–from history–you can still make up the friend (back in the day, people wrote a lot of letters). Ah, this gets slippery. Is the expectation that poetry is historical–a documentary? Or can it be historical fiction? I remember when Oliver Stone’s JFK came out, I thought it wrong that he (allegedly) played fast and loose with some of the facts. But it wasn’t a documentary.
Here’s an alternate solution: If your person is real and you can find a letter by her or him, use text from the letter interspersed by your persona’s thoughts while writing the letter.