Zionism

Zionism is a nationalist movement that advocates for the creation and support of a homeland for the Jewish people in the Land of Israel. 
The modern movement started in the late 19th century in Europe, as a reaction to increasing antisemitism and to ideas of assimilation. Zionism has had many different varieties that all shared the goal of creating a homeland for the Jewish People. The dominant variety at first was political Zionism, led by Theodor Herzl, but it later lost ground to the socialist Labor Zionism. 
In 1948, Zionism resulted in the creation of the state of Israel.
History.
Herzl and Political Zionism.
The word "Zionism" was first used in 1890. It comes from Zion, meaning Jerusalem, though it can also symbolically mean the Land of Israel as a whole. Jewish people at the time lived as minority groups among other nations all across the world, in what was called the diaspora. In the early 19th century, assimilation and legal emancipation were popular ideas among Jews in western Europe. However, in the late 19th century anti-Semitism became a bigger threat, with the 1881 Russian pogroms and the Dreyfus affair in France. This caused some Jewish thinkers to lose faith in the idea of ever being accepted in gentile societies. One of these thinkers was Theodor Herzl, who is often considered the father of modern Political Zionism. In his book, "the Jewish State," Herzl writes that the distinct status of Jews neither can, nor should, be changed. Instead he believed that antisemitism could be stopped by making the Jewish people a nation like any other, through giving them their own land. At the time there were multiple territories up for consideration, the most important being Argentina and Palestine. Herzl argues in favor of Palestine, thinking it would attract more people because of its status as the historic homeland of the Jews. Political Zionism was a secular movement and it was out of pragmatic considerations, rather than religious beliefs, that Palestine was chosen. In 1897 Herzl led the First Zionist Congress. There the Basel Program was adopted, espousing political Zionism and a Jewish homeland in the Land of Israel. The World Zionist Organization was created at the congress to support this goal. There were many more congresses after this, and at the fifth Zionist Congress in 1901 the Jewish National Fund was established with the goal of purchasing land in Palestine. 
Political Zionism wanted to work with the established powers to get a publicly recognized and legally assured homeland. Palestine at the time was under the control of the Ottoman Empire, but Herzl's attempts to get support from the Ottomans failed, and he had to appeal to the imperial powers of Europe. Herzl negotiated with British and Russian officials to use their influence to get official support for a Jewish homeland in Palestine, but this failed as well. In 1903 the British offered Herzl a Jewish homeland in Uganda instead, but this was eventually rejected by the Zionist congress. Only during World War I did the Zionist movement get the great power support they had been seeking. In 1917 the British signed the Balfour Declaration, wherein they declared that they "favour the establishment in Palestine of a national home for the Jewish people". Part of the British motivation in signing was getting support of Jews in Russia and the U.S.A. for the allied cause. After the war, the British Empire took control of Palestine and administered it as their own colony, the Mandate of Palestine. During this time the cooperation between the Zionist movement and the British continued, though there were still tensions. The alliance would fall apart just before World War II. 
Labor Zionism in Ottoman and British Palestine.
Organized Jewish migration into Palestine began after the pogroms of 1881 with the Hibbat Zion movement. However, even when they later joined forces with the Zionist congress it remained a small movement, as most Jewish migrants went to the United States. Only 3% of the Jews fleeing eastern Europe between 1881 and World War I went to Palestine. In the first wave of migration, known as the first Aliyah, the Jewish immigrants established agricultural colonies called moshavot. These settlements were poor, and so the immigrants turned to outside sponsors for help, who funded the development of other systems. The farms were turned into wine and citrus plantations based on the model of French Algeria, where they employed mostly cheaper Palestinian labor. Jewish workers had to compete with Palestinian workers, which lowered their wages. The immigrants of the second Aliyah of 1905 included many socialists. They thought that they needed higher wages for the Jewish workers in order to attract immigrants for the Zionist project. They wanted a "conquest of labor", fighting the landowners for better working conditions, but also trying to exclude Arab workers from these jobs to give them to Jewish workers. 
This was the beginning of Labor Zionism, which would overtake Political Zionism as the dominant variety after World War I. Labor Zionism was influenced by socialist ideals, and believed that to build a Jewish state a strong Jewish working class had to be created as well. They established farms called kibbutzim where all the workers collectively owned the land. In 1920 they formed the Histadrut, a trade union that eventually gained control of large sectors of the economy, becoming one of the largest employers for Jewish workers. The secretary of the Histadrut, David Ben-Gurion, became the unofficial leader of the Zionist movement in 1935 when he became chairman of the Jewish Agency. In 1948 he declared the establishment of a Jewish State in the Land of Israel and became Israel's first prime minister.