On the Launchpad you can see all your active events. Active events means, events where you are still working in and did not take place yet.
When an event has occurred, you can archive it. By archiving, you will keep all of your info in your event. Please note; the links such as briefings, production requests and crowd lists will not be available anymore once you archived the event. You can look into an archived event anytime, on the Launchpad beneath the active events.