The Universal Esperanto Association (UEA) association has two aims: to promote the use of the international language Esperanto, and to facilitate all relations, spiritual and material, among people, without distinction as to nationality, race, religion, politics, or language. This paper focuses on the contribution of the Esperanto movement to the furtherance of world peace and the bringing together of the peoples of the world. Its chief contribution toward this goal is its efforts to promote the use of Esperanto as a means of reducing and eventually eliminating what the UEA views as the crushing evil of language diversity, the chief if not sole cause of disunion in the human family. A universal language, namely Esperanto will contribute to the unity and brotherhood of humanity. The paper gives a detailed history of the Esperanto movement and its ideology and goals. Practical examples are provided of Esperanto's use for peacemaking and humanitarian purposes during the first and second World Wars. The cooperation and partnership of the Esperanto movement with UNESCO to help remove stereotypes and misrepresentations of people in the world's textbooks, and the various other activities, are discussed. (KFT)