for Supreme Court Associate Justice Felix Frankfurter. The justices would hold their weekly conference on Saturday, and Henkin would sleep on Frankfurter's couch on Friday nights and would refrain from writing while at the conference in order to avoid the performance of activities prohibited on Shabbat. In a 2003 interview, Henkin said that he "did my job as well as I could, observing Shabbat as well as I could" and said that he did not know if Frankfurter—who was not Shomer Shabbat—was ever aware that Henkin had been sleeping on his couch. Beginning in 1948, Henkin worked at the United Nations bureau of the United States Department of State, where he was one of the individuals responsible for the Convention Relating to the Status of Refugees in 1951, an agreement that established the internationally agreed upon definition of what constitutes a refugee and established the requirements for countries to provide asylum to individuals so designated. He left the State department in 1956 to teach for a year at Columbia University on the subject of nuclear disarmament which became the subject matter for his 1958 book Arms Control and Inspection in American Law. He taught at the University of Pennsylvania starting in 1958, continuing his work that was published as The Berlin Crisis and the United Nations in 1959 and the book Disarmament: The Lawyer's Interests, which was released in 1964. While teaching at Columbia Law School starting in the early 1960s and through the Justice and Society Program of the Aspen Institute, Henkin specialized in the development and instruction of human rights law, which he put into practice by establishing the university's Center for the Study of Human Rights in 1978 and creating the Human Rights Institute in 1998. Elisa Massimino, president and chief executive officer of Human Rights First, the nonpartisan organization originally formed by Henkin as the Lawyers Committee for Human Rights, said that he "literally and figuratively wrote the book on human rights" and that "[i]t is no exaggeration to say that no American was more instrumental in the development of human rights law than Lou". Written while Richard Nixon was conducting the American involvement in the Vietnam War, his 1972 book Foreign Affairs and the Constitution described the division of responsibility between the President of the United States and the Congress in conducting foreign affairs and military action, exploring how the executive branch had achieved a