Back in the day, one of the most valuable items to come into one's in-basket was an updated telephone directory. That's particularly true after a change of administration--it'd usually take 4 months or so for the reorganization to get done, people get assigned to new positions, and the data put into the directory. But once you had it in hand, you could spend a little time leafing through, seeing who had been assigned to a turkey farm and who had risen in the world. (That's especially true for someone like me, who tried to keep away from gossip, mostly because I wasn't any good at it. Those who participated in the grapevine would already know that so and so had taken his secretary with him to his new position, that the idiot son of a Congressman had landed in an assistant position, etc. etc.
More seriously, though is there anything more serious than climbing the greasy pole, from the telephone directory you could get a feel for the organization.
I launch into this subject to mourn the absence of any organizational directory for USDA or FSA. (USDA says they have one, but it's been unavailable for years.) You can search for individuals quite nicely, but you can't find positions. For example, who is the Executive Assistant to the Administrator, or has that position changed over the years? From a historical viewpoint, having similar charts of the organization from 1950, 1975, 2000, and 2014 would be instructive. I remember seeing the USDA level directory from the 1950's, about two pages of big shot jobs. These days it's probably 20 pages, if only we had one. Of course, only retired geezers have the time to worry about past history. :-)