Katzenelson participated in the Warsaw Ghetto Uprising starting on April 18, 1943
.Yitzhak Katzenelson (Hebrew: ??????? ????????, Yiddish: (??????? ????(?)???????(???; also transcribed Icchak-Lejb Kacenelson, Jizchak Katzenelson; Yitzhok Katznelson) (1886–1944) was a Jewish teacher, poet and dramatist. He was born in 1886 in Karelits near Minsk, and was murdered May 1, 1944 in Auschwitz.
In Vittel, Katzenelson wrote "Dos lid funem oysgehargetn yidishn folk" (Yiddish: "Song of the Murdered Jewish People"). He put the manuscript in bottles and buried them under a tree, from where it was recovered after the war. A copy was sewed into the handle of a suitcase and later taken to Israel.
Das Lied über die Ermordung des jüdischen Volkes.
Here's a Polish language version of one of the most famous Yiddish poets of the Holocaust: Icchak Kacenelson: Piesn o zamorodowanym zydowskim narodzie Warsaw: Czytelnik, 1986.
103 pages, entirely in Polish, in very good condition.