A fascinating chart about Fortune 250 law departments appears in a chapter of Laura Empson, ed., Managing The Modern Law Firm: New Challenges New Perspectives (Oxford Univ. Press 2007) at 92 (by Brian Uzzi, Ryon Lancaster and Shannon Dunlap). From 1992 to 1994, about 20 of the Fortune 250 had more than 60 lawyers (10 percent); from 1995 to 1997 the number crept up to about 40. Then, within the two years from 1998 to 2000 the number spiked to 100 – 40 percent of the largest 250 companies in the United States had 60+ attorneys, where the number vacillated the next two years between 80 and 120.
My supposition is that the rapid expansion in departments of such size resulted much more from mergers of companies and their legal teams than from organic headcount growth, or from a dramatic increase in legal volume or complexity (See my post of Jan. 16, 2009: layoffs after mergers with 9 references.). Some of the expansion may be due to lower-cost lawyers added in offices outside the US who swell the numbers (See my post of Sept. 21, 2005: arbitrage labor rates in different offices.).