He began reading, and writing letters, and in ten years accumulated a vast file of information.

Shortly before his death, Dr. Berger was asked to comment on the "Felash Mura", descendants of ancient Falasha whose families had long abandoned Judaism.

Berger was given an old prayer book written in Ge'ez and a circumcision knife by the community that he originally contacted as a thanks.

After his death, they were given by his family to the rabbi of a synagogue in New York he was a founding member of, the Pelham Jewish Center.

In 1989, the Graenum Berger Bronx Jewish Federation Service Center, a social welfare agency, was named in his honor.