stablished in 1892 as the International Kindergarten Union, the Association for Childhood Education International is the oldest professional association of its type in the United States.

On July 15, 1892, educators concerned with the professional preparation of kindergarten teachers gathered at the Baptist Church in Saratoga Springs, New York, to form the International Kindergarten Union (IKU). The educators sought to consolidate the gains made in early childhood education since the pioneering work of Friedrich Froebel, father of the kindergarten movement, in Germany during the 1820''s and 1830''s. They also planned collective action to promote kindergarten education at a time when traditional philanthropic support was dwindling and the public education establishment still resisted the concept of the kindergarten. The stated aims of the IKU were "to gather and disseminate knowledge of the kindergarten movement throughout the world, to bring into active cooperation all kindergarten interests, to promote the establishment of kindergartens, and to elevate the standard of professional training" for kindergarten teachers. The IKU acted to coordinate the efforts of local, regional, and national associations and to "collect, collate, and disseminate the valuable knowledge already attained, and to inspire greater and more intelligent efforts in the future."

During the first three decades of the twentieth century, public school systems gradually absorbed kindergarten education. As this happened, the methods and objectives of kindergarten and primary education developed an increasing influence upon one another. Reflecting this growing relationship, the National Council of Primary Education (established 1916) adopted a new constitution on February 24, 1931, that joined it with the International Kindergarten Union under the name Association for Childhood Education (ACE). As a preliminary to that action, the Union had adopted the new constitution and name the previous year. The aim of unification was to "bring greatly enlarged and more forceful influence to bear in promoting progressive nursery school, kindergarten, and primary worth throughout the country."