Gross-Breesen Letter 18 was published in April 1949 as a collection of letters, short messages, and addresses of former trainees at the so-called jüdische Auswandererlehrgut Gross-Breesen (Gross-Breesen Training Farm for Jewish Emigrants) in Silesia, established in 1936. Training courses in agriculture and handicrafts, as well as in housekeeping for young women, were supposed to increase the chances of young German Jews hoping to emigrate overseas and to prepare them for life in their future host countries.

The circular, which comprises both German and English-language texts, was compiled by the journalist Ernst Cramer (1913–2010). A former intern on the farm, he was able to emigrate to the United States in 1939 and, in April 1949, worked as deputy editor-in-chief for Die Neue Zeitung, a newspaper published by the US occupation authorities in Munich. Another leading figure in the publication of the circular alongside Cramer was the psychologist Curt Bondy (1894–1972), the former head of the training farm, who also fled to the United States. Some of the letters were directly addressed to him.

In 32 typed pages, Cramer compiled a selection of letters from Kenya, South America, the United States, Israel, and the Soviet Occupation Zone (SOZ). Many were only reproduced in abridged form. The circulars, which are also known as the Breesen Letters, were sent around the world at irregular intervals between 1938 and 2003, with their themes, contents, form, and editorship changing over the decades. Today, they are archived at the Leo Baeck Institute in New York. They allow for many interesting insights into the specific lived experiences of German-speaking Jews in the diaspora.