Newburger attended Columbia Law School, graduating from there with an LL.B. in 1874.[4] He then practiced law until 1890. Active in Tammany Hall, he unsuccessfully ran for the New York State Assembly. He was elected judge of the City Court in 1890, a position he held for five years. He was then elected to the Court of General Sessions, and in 1905 he was elected as a Tammany candidate Justice of the New York Supreme Court. When his term expired in 1919, Tammany chief Charles F. Murphy refused to back his candidacy for re-election due to differences that developed between them. In response, Newburger's friends formed an independent group to support his re-election campaign, the Republicans chose him as their candidate, and he was re-elected by a plurality of 80,000.[5] He retired in the end of 1923, when he reached 70 and the state's age limitation. In the beginning of 1924, he was appointed Official Referee of the Supreme Court.[4]
Active in Jewish societies, Newburger was one of the founders of the Jewish Theological Seminary of America.[6] He was president of Independent Order B'nai B'rith District No. 1, an executive committee member of the Independent Order Free Sons of Israel and the Order Kesher Shel Barzel, and a trustee of the Hebrew Free Schools.[3] He was a director and president of the Hebrew Orphan Asylum, and during his presidency the orphanage purchased a new site in the Bronx. He was also active in the Freemasons and Odd Fellows.[2]
^"United States Passport Applications, 1795-1925," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:QV5Y-VKR8: 16 March 2018), Joseph E Newburger, 1907; citing Passport Application, New York, United States, source certificate #31566, Passport Applications, January 2, 1906 - March 31, 1925, 36, NARA microfilm publications M1490 and M1372 (Washington D.C.: National Archives and Records Administration, n.d.).