When Adler retired about eighteen months later, Gottheil succeeded him. On taking charge he reorganized the religious school, and assisted in founding a theological school where preliminary training might be imparted to future candidates for the rabbinate. He prepared in 1886 the first Jewish hymn-book printed in America (with music in a separate volume by A. Davis); it contains not only traditional Jewish hymns, but also others of Christian origin, and upon it was based the Union Hymnal, which has since been generally adopted by the Reform congregations in the United States.
After Adler retired, Gottheil took over leadership of the religious school and helped establish a theological school to train future rabbis. In 1886, he published the first Jewish hymn book printed in America, featuring both traditional Jewish hymns and some Christian hymns, which later became the basis for the Union Hymnal used by many Reform congregations in the United States.