29 September 1892|
Cologne, Rhenish Prussia, Germany
|Died||12 March 1976
Kew Gardens, Queens, New York, United States
|Spouse(s)||Maria Hess (m. 1919)|
Born in Cologne into a wealthy Jewish family, Callmann earned a doctorate in law from the University of Freiburg in 1919. His studies had been interrupted by frontline service in World War I. In 1923, he entered his father's law firm in Cologne, and established himself as a leading authority on unfair competition and antitrust law. As a World War I veteran he was allowed to practice even after the Machtergreifung in 1933, but in 1936 decided to emigrated to the United States. He was offered a research fellowship at Harvard Law School, where he worked with Zechariah Chafee, while getting accustomed to American common law, and in 1939 he passed the bar exam. Between 1939 and 1945 he completed the American edition of his magnum opus on unfair competition, now (in revised edition) known as Callmann on Unfair Competition, Trademarks, and Monopolies.
- "Rudolph Callmann, 83, Dies; Lawyer Aided Jewish Refugees". New York Times. 15 March 1976.
- Baums, Theodor (1993). "Rechtsnorm und richterliche Entscheidung im Wettbewerbsrecht – Der Beitrag Rudolf Callmanns zur deutschen und amerikanischen Rechtsentwicklung". In Lutter, Marcus. Der Einfluß deutscher Emigranten auf die Rechtsentwicklung in den USA und in Deutschland (in German). Tübingen: Mohr. pp. 63–84. ISBN 3-16-146080-4.
- Stiefel, Ernst C.; Mecklenburg, Frank (1991). "Rudolf Callmann". Deutsche Juristen im amerikanischen Exil (1933–1950) (in German). Tübingen: Mohr Siebeck. pp. 126–127. ISBN 3161456882.
- Wadlow, Christopher (2011). "Rudolf Callmann and the Misappropriation Doctrine in the Common Law of Unfair Competition". Intellectual Property Quarterly (2): 110–153.