Isidor Mannheimer was born on 27 Mar 1885 in Bad Wildungen, Waldeck-Frankenberg, Hessen, Germany. He married Lina Lilienstein on 16 May 1919 in Gosfelden, Germany. He lived in Bad Wildungen, Waldeck-Frankenberg, Hessen, Germany between 1919–1932 at Lindenstrasse 12 . Isidor, his wife Lina, and children Erika and Herbert, were forced by the Nazis to leave their home in Bad Wildungen and move to Kassel. They lived in Kassel, Hessen, Germany between 1939–1941 at Banhoffstrasse 6. On Dec. 9, 1941, Isidor and his family were deported to the Riga Ghetto in Latvia, on a transport of 991 Jews. On 16 February 1942, he was sent to the concentration camp at Salaspils, 12 kilometers from Riga. On 26 March 26, 1942, one day before his 57th birthday, he was taken into the woods and shot by machine gun fire.