How did Hitler keep track of the Jews?

Answer 1

The Germans used census that had been gathered for decades. The Nazis started gathering these record starting in the early 1930's after Hitler came to power to first gather information on how many Jews lived in the cities, towns and villages and where they were. Most Jews did not lie when the census asked the religion as they did not think there was cause for alarm. This made it fairly easy to track them down when they started detaining, deporting and sending them to internment/concentration camps.

The Germans were very thorough in keeping meticulous records of who was detained and eventually sent to camps by assigning serial numbers that were recorded and usually placed on the prisoner's uniform and then by use of tattoos. For reasons unknown many of these records were never destroyed. These serial numbers were most often accompanied by badges or patches different shapes, symbols or letters which identified the status, nationality, or religion of the prisoner. In the death camps such as Auschwitz where the people were executed almost immediately after getting off the train tattoo were obviously not used but records were still kept.

A huge controversy started when it was found that IBM was contracted by the Nazis to create a punch card system that would efficiently keep track of the massive amount of Jews being processed. Previous to that time the numbers were written by hand similar to our census bureau forms used here until the last 4-5 decades.

Answer 2

They wanted to know where they were so they could kill them or move them to concentration camps. Hitler and Nazis wanted a certain group of people in Germany and the Jews were not in the plan they had. They wanted to know where they were so they could get rid of them.

Answer 3

Often neighbours noticed ... and some reported hidden Jews.

Answer 4

he had them register themselves.