The Star of David was a symbol that was mainly to recognize the Jews during the Holocaust. The Star of David is actually the emblem or symbol on Kind David's shield. They were forced to wear the stars on their clothes and with writing printed "Jews" in their language.
The Death March was an escape plan for the nazi to have the Jews move ahead because of the US coming in to try and save the Jews. They instead walked as far as they could while leaving the Jew with little to no food and water out in the cold to die. This was a way to hide evidence of the event and to lose some Jews in the process.