At the end of Act 1 of the famous play The Night Thoreau Spent in Jail by Robert E. Lee and Jerome Lawrence, Emerson visits Henry David Thoreau after he has been jailed. Thoreau's motivation for refusing to pay his poll taxes is a matter of conscience. He does not want to help pay for the Mexican-American War. Therefore, when Emerson asks what he is doing in jail, Thoreau counters by asking what Emerson is doing out of jail.

Although Thoreau and Emerson were close, there is no evidence that Emerson ever visited Thoreau during his real-life night in jail. Emerson encouraged Thoreau in his literary career and introduced him to other renowned writers. For a few years, Thoreau even moved into Emerson's home and was a tutor to his children. After Thoreau's sojourn at Walden Pond, he moved back to Emerson's home for a time to help out with the household.

Thoreau wrote a detailed account of his time in jail in the essay "Civil Disobedience," and he did not mention a visit by Emerson. He justified his decision to be jailed by stating:

Under a government which imprisons any unjustly, the true place for a just man is also a prison.

He wrote that though walls separated him and the townspeople, he felt free in his confinement. He found his time in jail interesting and his fellow prisoners amiable. He had a pleasant conversation with his cellmate. Thoreau clarified at the end of his account that: "This is the whole history of My Prisons." In other words, he had described the entire experience. Since he did not mention Emerson at all, we can assume that Emerson did not visit.

If your question is meant to ask if Emerson visited Thoreau during the real, historical events that inspired the play, the answer is that there is no way to know. Though the encounter between Emerson and Thoreau in the jail is one of the most well known in the play, there is no tangible evidence that those events ever actually transpired.

In regard to the play, Emerson did indeed visit Thoreau in jail in a scene that occurs in the first act. In the famous encounter, Emerson inquires as to why Thoreau is in jail, to which Thoreau responds with the question of why Emerson is not. This represents Thoreau's firm stance against the Mexican-American War and how Thoreau was unashamed to be spending a night in prison for protesting it.

While the playwrights of The Night Thoreau Spent in Jail were adept at weaving many actual Thoreau facts, events, and quotes into their text, one key scene is firmly fictitious. At the very least, it cannot be proven to be true. And it happens to be one that everyone remembers or recites. Even people who have never read the play or have never seen it performed seem to know these lines. It’s the memorable exchange that concludes Act 1, when Henry Thoreau is locked into the jail cell and Ralph Waldo Emerson comes to see him:

Waldo: Henry! Henry! What are you doing in jail?

Henry: Waldo! What are you doing out of jail?

Henry’s not-so-subtle point is that he is taking action against the injustices of government, while his friend Waldo is choosing not to do so. This brief but powerful dialogue is a terrific way to end the first act and to mirror the disagreements and disparate points of view that the two friends will face later on. But as far as we can tell, the scene never happened in real life. We have no proof that Emerson ever went to the jail the night Henry was behind bars, or that the great man was even in Concord that day. Neither man recorded such an encounter in their journals, writings, or letters; and none of their friends did, either. Henry’s Aunt Maria paid the poll tax during the night – not Aunt Louisa, as it happens in the play – and Henry was released the next morning to go on his way, to collect huckleberries, and to return to his house at Walden Pond. Whether or not he saw Emerson that day is left to speculation. It is possible that the next time the friends met, Emerson asked Thoreau why he had gone to jail. And Thoreau would have responded, “Why did you not?” But even a conversation like this one is not provable through primary or secondary sources.

Those of us who talk a lot about Thoreau with others -- especially in our capacities as tour guides and interpreters at sites around Concord, Massachusetts -- hear this scene repeated by unknowing visitors on a regular basis. They assume the dialogue is fact. We then have opportunities to put their assumptions into context and to be able to further discuss the night Thoreau spent in jail: both the real incident of 1846, as well as the 1970 play of the same name. This makes for an interesting juxtaposition.