SageMath is hosted on various mirrors worldwide. To find an old version: Visit the SageMath Download page . Select a mirror close to your location.
For commercial products like Sage 50 Accounting, the company typically supports the current version and the two previous years. Use the Sage Knowledgebase download old versions of sage
Look for the archive/ directory. Here, you can find versions dating back over a decade. GitHub Repository SageMath is hosted on various mirrors worldwide
Navigate to the /src/ (source code) or /bin/ (pre-compiled binaries) folders. download old versions of sage