Socrata allows you to keep snapshots of data that are published via API.  When a new version of the dataset is published, rolling versions of the previously published dataset will be kept.   The limits are based on plan and are as follows:

• Basic: 0
• Plus: 3
• Premium: 10
• Ultimate: Unlimited

If you have questions about your plan or are interested in moving to the next level of service, please contact your account manager.