I ended up spending a day researching at the DAR Library because one of my research partners for the day prefers its "open stack" arrangement over the Library of Congress. For you non-librarians, this means you can go directly to the shelves and retrieve most of the 185,000 volumes for yourself and browse related items shelved nearby. In a "closed stack" library, one must look up books in the catalog, fill out a request slip and wait for staff to retrieve books for you.
One misconception of the DAR Library that another of my researching partners had was that the library contained nothing more than lineage papers filed by aspiring members. Although these are another valuable resource in addition to the published volumes, the library contains 30,000 histories and genealogies many of which are said to be "unique or available in only a few libraries in the country." In addition the collection contains local histories, genealogical periodicals, city directories, and all kinds of materials on the Revolution and the late 18th Century.
In an earlier post to this blog, I discussed the Genealogical Research System (GRS) which gives access to an outline of lineages of members. During my visit I was told that within the next month or so there would be an online process for ordering and paying for the backup documents to the application documents that are more than 75 years old.
If you do visit and need sustenance during the day, the Clara Barton Cafe across the street to the north in the Red Cross complex offers a variety of food at reasonable prices and is open until about 2:00 PM.