The museum commemorating the World Trade Center and 9/11 has expanded enormously. “The memorial and its museum have quietly become an $800 million enterprise, $500 million of which must be privately raised. That’s almost five times the figure for the World War II Memorial in Washington, which honored the sacrifice of 400,000 soldiers and the service of some 16 million men and women. The museum alone is bigger than either the Whitney or the Ellis Island museums.”