Genealogy is prominently featured in the July 2008 issue of the Library of Congress' Wise Guide. The impressive genealogy collection of 50,000 genealogies and 100,000 local histories can trace it's beginning to 1815 and the acquistion of Thomas Jefferson's personal library.
Rising fuel costs keeping you from visiting the library in person? No problem: The loc.gov website is loaded with interactive exhibits including Exploring the Americas (loaded with 3,000 rare maps, documents, paintings, prints, and artifacts) and Creating the United States. You'll also find webcasts, and the extensive online catalogue.