Arnold D. Margolin participated in many political trials as counsel for the defense. In 1904 - he was one of the defenders of Jewish interests in the Homel pogrom trial. From 1905–1908 in many other pogrom trials. He was one of the defenders in the trial of Mendel Beilis. Father, David Margolin, was one of the Jewish leaders of the Jewish community in Kiev for decades and one of the most prominent pioneers of the steamer business, and many branches of industries in Ukraine. Mr. David Margolin has been president and Director of many industrial corporations in which Dr. Arnold Margolin also participated as a member of the Board of Director sand legal adviser. The David Margolin has built by his own means the largest Talmud Torah in Kyiv and presented it to the Jewish community of Kiev. Prior to the 1917 February Revolution in the Russian Empire he was Secretary General of the South Russian Branch of the Union. In 1918 he was appointed to the Supreme Court of the Ukrainian People's Republic and subsequently to the State Senate of the Ukrainian State. After the restoration of the Ukrainian People's Republic at the end of 1918 he became Assistant Minister of Foreign Affairs and a member of the Ukrainian delegation to the 1919-1920 Paris Peace Conference. In November 1919 — he was appointed to head of the diplomatic mission in London, and on 29 January 1920 he arrived in London to take up his post. On 16 July 1920 he tendered his resignation. He prepared a case for the admission of the Ukrainian People's Republic to the League of Nations. In 1922 — he emigrated to the United States where he practiced as a lawyer and lectured in history at several universities. Arnold Margolin was active in several Ukrainian émigré scholarly institutions and promoted Ukrainian-Jewish mutual understanding. He served on the staff of the U.S. Office of Strategic Services during World War II. From 1948 — 1949 — dean of the Army's European Command Intelligence School for Army. From 1954 — 1955 — he was the first president and professor of law at of the Ukrainian Technical Institute in New York City.
Publications
The Criminal Law Kiev, 1907
Lombroso's Role and Significance in the Evolution of View on Crimeand Punishment Kiev, 1908
From a political diary; Russia, the Ukraine, and America, 1905-1945 by A. D Margolin
The Jews of eastern Europe by A. D Margolin
Ukraine and Policy of the Entente. by A. D Margolin
Osnovy gosudarstvennogo ustroĭstva SShA by A. D Margolin
Ukraine and policy of the Entente by A. D Margolin
Osnovnyia cherty novago ugolovnago ulozhenīia kriticheskīĭ ocherk s predislovīem... R. Garro, Ėlement chuvstva v institutia nakazanīia i drugīia stat'i by A. D Margolin
Aperçu critique des traits fondamentaux du nouveau Code pénal russe : rapport lu à la Société juridique près l'Université de Kieff le 20 septembre 1903 by A. D Margolin
Derzhavnyĭ ustriĭ Spoluchenykh Shtativ Ameryky by A. D Margolin
V polosia likvidatsīi : ocherki, riechi, kassatsīonnyia zhaloby by A. D Margolin