No insult intended... just a p/t
a. to unearth or bring to notice: We dredged up some old toys from the bottom of the trunk.
b. to locate and reveal by painstaking investigation or search: Biographers excel at dredging up little known facts.

To bring up the past... reanimate that which has been done before (colloq.)

::edit:: I sense a disturbance in the force...