The decision to build a camp near Lublin came from Heinrich Himmler during his visit to Lublin in July of 1941. By October, an official order for the establishement of the camp had already been given and construction had begun. The Nazi's brought in Polish Jews from the labor camp on Lipowa street to start building the camp. Though these prisoners worked on the construction of Majdanek, they were housed at the Lipowa street labor camp each night.
The Nazi's soon brought in 2,000 Soviet prisoners of war to build the camp. These prisoners worked and lived inside Majdanek. With no barracks, the prisoners were forced to work and sleep in the cold outdoors with no water or toilets. As you can imagine, there was an extremely high mortality rate among these prisoners.
The camp itself is located on a completely flat field. Unlike most other camps, the Nazi's didn't try to hide this one from view. Instead, it bordered on the city of Lublin and could easily be seen from the road.
Originally the camp was expected to hold between 25,000 and 50,000 prisoners. By the beginning of Dec. 1941 a new plan was being considered to expand Majdanek in order to hold 150,000 prisoners. And then again, designs for the camp were discussed to eventually hold 250,000 prisoners.
Though the Nazi's had increased their expectations for the capacity of Majdanek, construction came almost to a halt in the spring of 1942. Construction materials couldn't be sent to Majdanek because supplies and railways were being used for the urgent transports needed to supply the German soldiers on the eastern front. Though the camp did have a few additions in the spring of 1942, the camp never grew much more after it reached a capacity of 50,000 prisoners.
The camp was liquidated in July of 1944, but it was only partially destroyed by the time the Red Army arrived. Although 1,000 prisoners had been evacuated on a death march, the Red Army was able to find thousands of prisoners still in the camp, and ample evidence of the mass murders that had taken place at Majdanek.