Companies, labor unions, trade associations and other influential organizations spend billions of dollars each year to lobby Congress and federal agencies. Some special interests retain lobbying firms, many of them located along Washington's legendary K Street; others have lobbyists working in-house. We've got totals spent on lobbying, beginning in 1998, for everyone from AAI Corp. to Zurich Financial. (See also: Foreign Lobby Watch.)

Total Spending & Lobbyists See numbers adjusted for inflation

*The number of unique, registered lobbyists who have actively lobbied.