The import manager can be found in user drop down menu in administration. To view the user drop down menu, click on your name next to admin options. In the menu that appears, click on the Import Manager button, which opens the import manager window.

The import manager displays a list of all your incomplete imports. Clicking on an incomplete import will open the import page for that import. Note that you will only see your incomplete imports, you will not see imports started by anyone else.