Country of Origin
The grandmother of Sarah, Moses, and Boris Rabinowitz brought the children to Juarez, Chihuahua, Mexico from Russia in 1924. She abandoned them a few years later and went to Canada.
This document is very long and contains many, many letters most of which deal with trying to get the children to Canada to be with their grandmother. There are complications; the grandmother entered Canada illegally, the boys are young and don't have passports, and appear to be troublemakers. The U.S. won't allow the boys to enter and Canada won't allow entry without Mexican passports which they can't get.
The grandmother and Sarah end up returning to Russia.