The Campaigns Dashboard will show regular sent campaigns for 45 days past their send date.
Triggered campaigns will show the previous send and the next scheduled send.
The purpose for this cap is to keep this view clean and easy to navigate especially for users with daily or hourly triggered campaigns. If you are looking for a campaign older than those shown on the Dashboard page, use the Find Campaigns search function.
Campaigns included in an automation will show on the Automation Dashboard.