Library The Library of Congress was established by an act of Congress in 1800. It is primarily housed in three buildings on Capitol Hill, but also includes several other sites: the National Library Service for the Blind and Physically Handicapped in Washington, D.C.; the National Audio-Visual Conservation Center in Culpeper, Virginia; a large book storage facility located at Fort Meade, Maryland; and multiple overseas offices. The Library had mostly law books when it was burned by a British raiding party during the War of 1812, but the library's collections were restored and expanded when Congress authorized the purchase of Thomas Jefferson's private library. One of the library's missions is to serve Congress and its staff as well as the American public. It is the largest library in the world with nearly 150 million items including books, films, maps, photographs, music, manuscripts, graphics, and materials in 470 languages. Research The Congressional Research Service, part of the Library of Congress, provides detailed, up-to-date and non-partisan research for senators, representatives, and their staff to help them carry out their official duties. It provides ideas for legislation, helps members analyze a bill, facilitates public hearings, makes reports, consults on matters such as parliamentary procedure, and helps the two chambers resolve disagreements. It has been called the "House's think tank" and has a staff of about 900 employees. Budgeting The Congressional Budget Office or CBO is a federal agency which provides economic data to Congress. It was created as an independent non-partisan agency by the Congressional Budget and Impoundment Control Act of 1974. It helps Congress estimate revenue inflows from taxes and helps the budgeting process. It makes projections about such matters as the national debt as well as likely costs of legislation. It prepares an annual Economic and Budget Outlook with a mid-year update and writes An Analysis of the President's Budgetary Proposals for the Senate's Appropriations Committee. The speaker of the House and the Senate's president pro tempore jointly appoint the CBO director for a four-year term. Lobbying Lobbyists represent diverse interests and often seek to influence Congressional decisions to reflect their clients' needs. Lobby groups and their members sometimes write legislation and whip bills. In 2007, there were approximately 17,000 federal lobbyists in Washington, D.C. They explain to legislators the goals of their organizations. Some lobbyists represent non-profit organizations and work pro bono for issues in which they are personally interested. Police