In the 1920s, concern over the varying quality of emerging nursery school programs in the United States inspired Patty Smith Hill to gather prominent figures in the field to decide how to best ensure the existence of high-quality programs. Meeting in Washington, DC, the group negotiated the issue of a manual, called "Minimum Essentials for Nursery Education," that set out standards and methods of acceptable nursery schools. Three years later, the group cemented the existence of a professional association of nursery school experts named the National Association for Nursery Education (NANE).