Source- https://encyclopedia.ushmm.org/content/en/article/sachsenhausen

snip-"The SS established the Sachsenhausen concentration camp as the principal concentration camp for the Berlin area. Located near Oranienburg, north of Berlin, the Sachsenhausen camp opened on July 12, 1936, when the SS transferred 50 prisoners from the Esterwegen concentration camp to begin construction of the camp."

snip-"Prisoners in the Camp
In the early stage of the camp's existence the SS and police incarcerated mainly political opponents and real or perceived criminal offenders in Sachsenhausen. By the end of 1936, the camp held 1,600 prisoners. Between 1936 and 1945, however, Sachsenhausen also held Jews, gay men, Jehovah's Witnesses, "asocials" (among these prisoners were Roma and Sinti), and, later, Soviet civilians. Prominent figures interned in Sachsenhausen included Pastor Martin Niemöller, former Austrian chancellor Kurt von Schuschnigg, Georg Elser, Herschel Grynszpan, and Joseph Stalin's son, Yakov Dzhugashvili.

The number of Jewish prisoners in Sachsenhausen varied over the course of the camp's existence, but ranged from 21 at the beginning of 1937 to 11,100 at the beginning of 1945. During the nationwide Kristallnacht ("Night of Broken Glass&quot pogrom of November 1938, Reichsführer SS (SS chief) and Chief of German Police Heinrich Himmler ordered the arrest of up to 30,000 Jews. The SS transported those arrested to Sachsenhausen, Dachau, and Buchenwald concentration camps. Almost 6,000 Jews arrived in Sachsenhausen in the days following the Kristallnacht riots."



Much more there.

If you don’t count Native American reservation, America first concentration camps were in the Phillipines