In 1956, Mary White held the first meeting of La Leche League in her living room, in response to a report that said only 20% of American women were breastfeeding their babies. She felt that breastfeeding could provide a superior form of nutrition for infants, and also that it improved the psychological relationship between children and their mothers. Concerned about the dropping breastfeeding rate in the United States, she decided to start an advocacy organization to talk to nursing mothers about breastfeeding. By 1964, La Leche League had become La Leche League International, thanks to members in Mexico, Canada, and New Zealand.

Today, La Leche League has members all over the world who breastfeed their children, provide support to nursing mothers, offer lactation consultation, and help to improve the quality of obstetrics, along with pre and post natal care, in developing nations. La Leche League initiatives have also been behind “baby friendly hospitals” and reformed attitudes in the medical community about breastfeeding and nursing mothers. Members of La Leche League include nursing mothers, supportive fathers, and health care professionals who want to keep abreast of recent medical developments while providing the best possible support to their patients. In addition to an annual conference, La Leche League also provides regional workshops, along with one on one consultation for pregnant and nursing mothers.

La Leche League believes that breast milk is the optimal food for developing infants, and also that the psychological bond stimulated by breastfeeding is beneficial for infant development and maternal health and well being. According to La Leche League, breastfed babies are happy babies, and so are their mothers, who are providing their infants with all the nutrition they need. La Leche League also believes that the support of a father or partner is crucial to infant development, and than breastfeeding should continue until a baby is ready to switch to solids. By promoting breastfeeding, La Leche League hopes to build healthy families and stronger societies.

Many lactavists are members of La Leche League, because they agree with the stated beliefs and mission of the organization. Because many of the members are mothers, La Leche League provides the unique service of support from nursing moms to expecting and nursing mothers, while also working with doctors and other health care providers. In addition, La Leche League International works to establish protections for breastfeeding mothers under the law, including the right to breastfeed in public, access to clean, calm rooms to nurse in while at work, and negotiating terms for breastfeeding mothers involved in family law disputes.