NORAD 9/11 Timeline
The History Commons is an amazing resource for researchers.
It contains summaries of 16,238 events, which are published on the website in the format of dynamic timelines. These timelines can be filtered by investigative project, topic, or entity (e.g., a person, organization, or corporation). You can even generate a “scalable context” timeline for any event in the History Commons database simply by clicking the date of the timeline entry. You can search for events by using the search box or by browsing through the list of projects.