The Holocaust: The MS St. Louis, a ship carrying 973 German Jewish refugees, is denied permission to land in Florida, in the United States, after already being turned away from Cuba. Forced to return to Europe, more than 200 of its passengers later die in Nazi concentration camps.

The Holocaust, known in Hebrew as the Shoah, was the genocide of European Jews during World War II. From 1941 to 1945, Nazi Germany and its collaborators systematically murdered some six million Jews across German-occupied Europe, around two-thirds of Europe's Jewish population. The murders were committed primarily through mass shootings across Eastern Europe and poison gas chambers in extermination camps, chiefly Auschwitz-Birkenau, Treblinka, Belzec, Sobibor, and Chełmno in occupied Poland. Separate Nazi persecutions killed millions of other non-Jewish civilians and prisoners of war (POWs); the term Holocaust is sometimes used to include the murder and persecution of non-Jewish groups.

MS St. Louis was a diesel-powered ocean liner built by the Bremer Vulkan shipyards in Bremen for Hamburg America Line (HAPAG). She was named after the city of St. Louis, Missouri. She was the sister ship of Milwaukee. St. Louis regularly sailed the trans-Atlantic route from Hamburg to Halifax, Nova Scotia, and New York City, and made cruises to the Canary Islands, Madeira, Spain, and Morocco. St. Louis was built for both transatlantic liner service and for leisure cruises.

Between 1933 and 1945, a large number of Jews emigrated from Nazi Germany and German-occupied Europe. This exodus was triggered by the militaristic antisemitism perpetrated by the Nazi Party and by Germany's collaborators, ultimately culminating in the Holocaust. However, even before the genocide itself, which began during World War II, the Nazis had widely sponsored or enforced discriminatory practices—by legislation, in many cases—against Jewish residents, such as through the Nazi boycott of Jewish-owned businesses. Although Adolf Hitler and the German government were initially accepting of voluntary Jewish emigration from the country, it became difficult to find new host countries, particularly as the 1930s were marked by the Great Depression, as the number of Jewish migrants increased. Eventually, the Nazis forbade emigration; the Jews who remained in Germany or in German-occupied territory by this point were either murdered in the ghettos or relocated to be systematically exploited and murdered at dedicated concentration camps and extermination camps throughout the European continent.