The United States Holocaust Memorial Museum (USHMM) provides for the documentation, study, and interpretation of Holocaust history from 1933 to 1945. It is dedicated to helping leaders and citizens of the world confront hatred, prevent genocide, promote human dignity, and strengthen democracy.
The USHMM’s collections contain more than 12,750 artifacts, 49 million pages of archival documents, 80,000 historical photographs, 200,000 registered survivors, 1,000 hours of archival footage, 84,000 library items, and 9,000 oral history testimonies. It also has teacher fellows in every state in the United States and almost 400 university fellows from 26 countries since 1994.
Researchers at the United States Holocaust Memorial Museum have documented 42,500 ghettos and concentration camps erected by the Nazis throughout German-controlled areas of Europe from 1933 to 1945.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.