From late 1935 to early 1951, he lived in the U.S. and was an advisor in cartel matters and on the German question after WW II.
[3] At the end of 1935, Kronstein emigrated with his family to the United States and first tried to work in New York City as a consultant on foreign law.
[4] Kronstein worked initially or predominantly for the Claims Division, but had reservations about having to confiscate German assets after America entered the war against Germany.
From the beginning on, he did important work for this division: In front of the Senate Commission on Patent Affairs Kronstein suggested that the cartelized economic structure of Germany had facilitated Hitler the seizure of power.
[5] In the Department of Justice, he was also a member of the so-called Antimonopoly Committee, which dealt with the reconstruction of Europe after the war.