How do I use the API to query for closed projects.
Use this query to give you a list of all closed projects within a workspace.
https://rally1.rallydev.com/slm/webservice/v2.x/workspace/<WorkspaceOID>/projects?includeClosedProjects=true&ignoreClosed=true&pagesize=2000&query=(State%20=%20Closed)
This article has details about how to find the Workspace ObjectID (or WorkspaceOID). Find the ObjectID (OID) of Projects, Workspaces, Timeboxes and Artifacts