Yes, it's listed as a Tether to Destiny. That's old news.

There's no especial mystery about the recent switch: Yves simply decided that the Tether was better suited being run by Beth. This isn't Hell, after all: it's perfectly reasonable for one Archangel to hand over a Tether to another, providing that both are on good terms and willing to be accommodating. It wasn't like Servitors of Archives weren't (constantly) using the Library of Congress constantly all along: in fact, they were using it more than Yves' Servitors were (which was no doubt a factor in the switch). The Heavenly focus of the Tether didn't even shift.

Anyway, for those who aren't familiar with the Tether, the Library of Congress is the symbol of Library Science in the United States. It's said that every book published in the USA after a certain point ends up in the archives somewhere: this is an exaggeration, but not much of one. The architecture of the building most visited by tourists resembles a secular temple dedicated to Knowledge: the floors, walls and ceilings commemorate virtually every form of secular learning known to man. The overall effect (including stained glass windows) should be hideously overdone, but isn't, strangely enough. The sight of stoic librarians (or library students) breaking down and weeping at the sight of all those books is not unknown.

The focus of the Tether has always been the collective area where the original volumes donated by Thomas Jefferson were stored. Naturally, this normally means that descending celestials may find themselves virtually anywhere in the Thomas Jefferson Building (which is what most celestials mean when they say 'the Library of Congress Tether'. It's actually one of three buildings). However, at the moment these volumes are on display on the Northwest Pavilion on the Tether's second floor. The current Seneschal (Thomas, Kyriotate of Archives) arranged the display so that a visitor appears to be inside a circular room: this both appeals to his sense of humor and strengthens the focus. More than one potential Soldier has been identified by his or her reaction to the Tether's focus.

Thomas (no relation) has been Seneschal of the Tether since it formed in 1899, and had no difficulty in switching Superiors. He didn't even have to be given any new Choir or Servitor Attunements: he was always on good terms with Beth. Thomas' duties likewise remain unchanged: keep one eye on the books, another on the researchers, a third on the area (he's close to the Capitol building, after all) and a fourth out for any potential Soldiers of Destiny and/or Archives. This is where being a Kyriotate comes in handy.

Needless to say, he's got help. Every Librarian of Congress since 1900 has known of Thomas' presence, although none of them so far have been actually Soldiers (some of their subordinates have been, though). In emergencies, Thomas has no shortage of hosts to help him defend the Tether. The Kyriotate is often in one host or another: he's noted (strictly off the record) as being an expert on the arcane cataloging system, which can speed up the process considerably...

Library of Congress (Thomas Jefferson Building) Tether: Strong Tether (16 Forces, High Flow, Celestial Harbor, Friendly, Quiet)