AḤDUT HA-AVODAH , Zionist Socialist Labor Party in Palestine founded in 1919. First steps toward its formation were taken in 1918 by soldiers of the *Jewish Legion at Tell el Kabir, Egypt, where many Palestinian Jewish workers and members of *Po'alei Zion from America were serving as volunteers in the Jewish battalions of the British Army. The majority of the volunteers belonged to an influential non-party group, led by Berl *Katznelson and Shemuel *Yavneeli, and to Po'alei Zion, led by Izhak *Ben-Zvi and David *Ben-Gurion. There were also a few volunteers who were leading members of the other Labor Party, *Ha-Po'el ha-Ẓa'ir, among them Levi Shkolnik (*Eshkol) and Abraham Haft, although their party objected to participation in the Legion. In February 1919, a conference of Po'alei Zion unanimously called for unity, but a Ha-Po'el ha-Ẓa'ir conference rejected the proposal. Immediately afterward, at Petaḥ Tikvah, a conference of the Agricultural Workers' Union, which included members of both parties, voted 48 to 12 for the establishment of a workers' federation to be responsible for all political, economic, and cultural activities, and for settlement on the land. Most Ha-Po'el ha-Ẓa'ir members did not join, but established separate labor exchanges and a separate agricultural settlement center. A founding conference resulting from the agricultural workers' decision was elected by 1,871 workers, with 47 rural delegates, 15 urban, and 19 representing the legionnaires from abroad. It met shortly afterward and decided to establish the Zionist Socialist Federation of the Workers of Ereẓ Israel, Aḥdut ha-Avodah, as an autonomous body, comprising all workers and members of the professions living solely from their labor without exploiting others. It was to participate in the World Zionist Organization and the Socialist International; to organize the provision of work, cooperative supplies, vocational training, and general education; to protect the workers' dignity and interests; and to enhance the creative capacity of the working class. Aḥdut ha-Avodah aspired, through organized mass immigration, to mold the life of the Jewish people in Ereẓ Israel as a commonwealth of free and equal workers living on its labor, controlling its property, and arranging its distribution of work, its economy, and its culture. Only a minority of Ha-Po'el ha-Ẓa'ir members joined, and, in order to avoid competition in labor matters, both groups agreed to establish the General Federation of Jewish Workers in Ereẓ Israel (*Histadrut), which was founded in December 1920. Aḥdut ha-Avodah became dominant in the Histadrut, of which Ben-Gurion was elected secretary-general. It also became dominant in the Elected Assembly of the yishuv, but continued to aim at complete workers' unity. After prolonged negotiations, Aḥdut ha-Avodah and Ha-Po'el ha-Ẓa'ir merged in 1930 to form Mifleget Po'alei Ereẓ Israel (*Mapai).
A study of Aḥdut ha-Avodah, Aḥdut ha-Avodah ha-Historit, by Jonathan Shapiro (1975) traces the consolidation of the party out of various factions and how the veteran leadership from the Second Aliyah period kept the reins of power in their hands. Shapiro attributes the party's organizational strength to its social and ideological roots going back to the Jewish experience in Russia.
G. Kressel, Mafte'aḥ la-Kunteres, 1919–1945 (1945).