Born in Belorussia, he applied to the Slutzker Yeshiva under R. Isser Zalman Meltzer at a tender age. When R. Isser Zalman tested him on Tractate Eruvin, he soon realized that the boy knew it better than he. In addition to R. Meltzer, he was ordained by R. Boruch Ber Leibowitz and the Aruch HaShulchan. After serving as rabbi and Yeshiva head in a number of Russian towns, he emigrated to America in 1922 and in 1925 became Director of Ezras Torah, which provided assistance to scholars. He served in that capacity until his death. He was paid a meager salary and when he attained an advanced age and reduced his work day, he insisted that his salary be correspondingly reduced.
Rav Henkin was one of the leading Halachic authorities of his generation and was particularly expert in the laws of divorce. He was thoroughly knowledgeable concerning the issues of the day and wrote many articles expressing his frequently critical viewpoint. He urged each community to hire a dayan, besides the rabbi, who could decide all questions of halacha. He strongly attacked self-styled Jewish leaders who jeopardized Jewish lives to advance their political ambitions. He held that witnessed civil marriages were halachically binding. He believed that once the State of Israel was established it should be supported by all Jews, except in matters contrary to Torah. Most of his writings are collected in two volumes printed by Ezras Torah.
Indicative of the esteem in which Rav Henkin was held, is R. Yaakov Kamenetzkys statement at Rav Henkins funeral that he had always thought that Rav Henkin would be our representative to greet the Messiah.
Sources: Orthodox Union