As the mass shootings continued in Russia, the Germans began to search for new methods of mass murder. This was driven by a need to have a more efficient method than simply shooting millions of victims. Himmler also feared that the mass shootings were causing psychological problems in the SS. His concerns were shared by his subordinates in the field.[251] In December 1939 and January 1940, another method besides shooting was tried. Experimental gas vans equipped with gas cylinders and a sealed compartment were used to kill the disabled and mentally-ill in occupied Poland.[252] Similar vans, but using the exhaust fumes rather than bottled gas, were introduced to the Chełmno extermination camp in December 1941,[253] and some were used in the occupied Soviet Union, for example in smaller clearing actions in the Minsk ghetto.[254] They also were used for murder in Yugoslavia.[255]

At the end of the war, between 50,000 and 100,000 Jewish survivors were living in three zones of occupation: American, British and Soviet. Within a year, that figure grew to about 200,000. The American zone of occupation contained more than 90 percent of the Jewish displaced persons (DPs). The Jewish DPs would not and could not return to their homes, which brought back such horrible memories and still held the threat of danger from anti-Semitic neighbors. Thus, they languished in DP camps until emigration could be arranged to Palestine, and later Israel, the United States, South America and other countries. The last DP camp closed in 1957 (David S. Wyman, "The United States," in David S. Wyman, ed., The World Reacts to the Holocaust, Baltimore, MD: Johns Hopkins University Press, 1996, pp. 707­10).
The impact of the Holocaust varied from region to region and from year to year in the 21 countries that were directly affected. Nowhere was the Holocaust more intense and sudden than in Hungary. What took place over several years in Germany occurred over 16 weeks in Hungary. Entering the war as a German ally, Hungary had persecuted its Jews but not permitted the deportation of Hungarian citizens. In 1941 foreign Jewish refugees were deported from Hungary and were shot by Germans in Kam’yanets-Podilskyy, Ukraine. After Germany invaded Hungary on March 19, 1944, the situation changed dramatically. By mid-April the Nazis had confined Jews to ghettos. On May 15, deportations began, and over the next 55 days the Nazis deported more than 437,000 Jews from Hungary to Auschwitz on 147 trains.
Relying on a surveying device known as a total station—the tripod-mounted optical instrument employed by construction and road crews—Reeder set about measuring minute elevation changes across the land, searching for subtle gradations and anomalies. He zeroed in on a hummock that looked like the earthen side of a bunker, long since overgrown with moss and foliage, and roughly 100 feet away, a telltale dip in the earth.

Along with several other Auschwitz doctors, Mengele transferred to Gross-Rosen concentration camp in Lower Silesia on 17 January 1945, taking with him two boxes of specimens and the records of his experiments at Auschwitz. Most of the camp medical records had already been destroyed by the SS[57][58] by the time the Red Army liberated Auschwitz on 27 January.[59] Mengele fled Gross-Rosen on 18 February, a week before the Soviets arrived there, and traveled westward to Žatec in Czechoslovakia, disguised as a Wehrmacht officer. There he temporarily entrusted his incriminating documents to a nurse with whom he had struck up a relationship.[57] He and his unit then hurried west to avoid being captured by the Soviets, but were taken prisoners of war by the Americans in June 1945. Although Mengele was initially registered under his own name, he was not identified as being on the major war criminal list due to the disorganization of the Allies regarding the distribution of wanted lists, and the fact that he did not have the usual SS blood group tattoo.[60] He was released at the end of July and obtained false papers under the name "Fritz Ullman", documents he later altered to read "Fritz Hollmann".[61]
The Soviet Army reached Auschwitz on January 27, 1945. By that time, an estimated 1,500,000 Jews, along with 500,000 Polish prisoners, Soviet POWs and Gypsies, had perished there. As the Western Allies pushed into Germany in the spring of 1945, they liberated Buchenwald, Bergen-Belsen, and Dachau. Now the full horror of the twelve-year Nazi regime became apparent as British and American soldiers, including Supreme Commander Dwight D. Eisenhower, viewed piles of emaciated corpses and listened to vivid accounts given by survivors.
The Wannsee Conference, a meeting between the SS (the elite guard of the Nazi state) and German government agencies, opens in Berlin. They discuss and coordinate the implementation of the "Final Solution," which is already under way. At Wannsee, the SS estimates that the "Final Solution" will involve 11 million European Jews, including those from non-occupied countries such as Ireland, Sweden, Turkey, and Great Britain. Between the fall of 1941 and the fall of 1944, the German railways transport millions of people to their deaths in killing centers in occupied Poland.
The Holocaust did not happen a day. It grew for 2000 years un till it peaked. Weather Hitler was there or not to take advantage of the moment . Or weather he was there to cause it to peak is debatable. It happened because nobody would stop it. 'The killing stopped in 1944 the anti-Semitism did not''. Anti-Semitism led to the final solution. Which was the Nazis plan to kill all the Jews in Europe. It was carried out by killing squads ,ghettos, and camps. The Final Solution was personal but it was also a project. It was not just the actions of Hitler but a plan carried out by the world. ''Jews are not humans''. Or that's what some of the soldiers said. With a national precipitation it was easy for cruel and mean acts to be committed. Nazis rounded up Jehovah's witnesses and homo sexual and sent them to cams to be gassed. Homo Sexual were forced to wear a pink triangle periling the star of David.
'Righteous Gentiles' is the phrase used for those non-Jews who risked their lives to save Jews during the Holocaust. At Yad Vashem Museum in Jerusalem, over 11,000 'Righteous Gentiles' are honored; almost 5,000 are Polish. What follows are profiles and oral histories of ten Polish rescuers of Jews. Their stories reveal what transforms people from indifferent bystanders into heroic saviors
During the era of the Holocaust, German authorities also targeted other groups because of their perceived racial and biological inferiority: Roma (Gypsies), people with disabilities, and some of the Slavic peoples (Poles, Russians, and others). Other groups were persecuted on political, ideological, and behavioral grounds, among them Communists, Socialists, Jehovah's Witnesses, and homosexuals.
In June 1941, Mengele was posted to Ukraine, where he was awarded the Iron Cross 2nd Class. In January 1942, he joined the 5th SS Panzer Division Wiking as a battalion medical officer. After rescuing two German soldiers from a burning tank, he was decorated with the Iron Cross 1st Class, the Wound Badge in Black, and the Medal for the Care of the German People. He was declared unfit for further active service in mid-1942, when he was seriously wounded in action near Rostov-on-Don. Following his recovery, he was transferred to the headquarters of the SS Race and Settlement Main Office in Berlin, at which point he resumed his association with von Verschuer, who was now director of the Kaiser Wilhelm Institute of Anthropology, Human Heredity, and Eugenics. Mengele was promoted to the rank of SS-Hauptsturmführer (captain) in April 1943.[20][21][22]