The following historical outline has been widely accepted by believers in the Urantia Book, though the lack of firsthand documentation makes it impossible to verify its accuracy.

Sometime between 1906 and 1911, in Chicago, a man in his sleep began to transmit communications from celestial personalities. Subjects included the nature of God, the structure of the universe and its divinely planned development, the angelic hierarchy, life on other planets, the origin and history of our world (known as Urantia), the life and teachings of Jesus, life after death, and our eternal destiny as citizens of a friendly universe.

The scope of knowledge and depth of wisdom of the communications were so extraordinary, that the man became a patient of Dr. William S. Sadler, a well-known psychiatrist and author. The doctor, a noted debunker of spiritualism, was forced to take the case seriously and stenographers were called in to transcribe the voluminous material.

Dr. Sadler, his wife Lena, their son Bill, their adopted daughter Emma (Christy) Christensen, Lena’s sister Anna Kellogg and Anna's husband Wilfred Kellogg became the custodians of the manuscripts and were known as the "contact commission.” The transmitter of the information was known as “the contact personality” or “the sleeping subject.” His name was never revealed.

Around 1924 the Sadlers began inviting individuals to weekly meetings at their residence at 533 Diversey Parkway, to study and discuss the teachings that were coming through. This group grew to hundreds who came and went through the years. They were encouraged to ask questions, and the content of the papers would sometimes be modified by the celestial revelators in response. The members of this group, known as the Forum, signed a pledge of secrecy not to discuss the material outside their group.

The Forum in 1934

In 1941 Harold and Martha Sherman were introduced to the revelations by Harry Loose, a former Forumite with mysterious connections to the phenomena, and they joined the Forum. To study the material more closely they moved to Chicago and lived across the street at 530 Diversey Parkway from May 1942 until May 1947. Their fifteen handwritten notebooks describing the Forum sessions and the teachings themselves survive as what may be the only firsthand record and have been published as The Sherman Diaries.

In 1955 the completed series of papers was published as The Urantia Book, since 2002 in public domain. [Read or download the Square Circles Publishing version online ]

In 1976 Harold Sherman wrote a book called How to Know What to Believe, which included a chapter on their experiences with the Urantia Forum entitled "Pipeline to God."