1
general::
Follow successfully, locate, as in I've been trying to track down that book but haven't had any luck. This term alludes to the literal use of track, "follow the footsteps of." [Second half of 1800s]
American Heritage Idioms
2
general::
Phrase(s): track someone or something down
to search out where someone or something is. • I don’t know where Anne is. I’ll try to track her down. • I’ll track down Anne for you.
McGrawhill's American Idioms And Phrasal Verbs