Welcome to the 2017 NLJ 500, an annual survey that debuted nearly 40 years ago with 200 firms. In this year's report, the number of lawyers working at the nation's 500 largest U.S.-centric law firms in 2016 grew by about 2 percent from the previous year, to 163,700. The average lawyer count per firm bumped up slightly, to 327.

We look beyond the overall totals to explore intriguing growth shifts at individual firms, as well as what one analyst called firms' “continuous recalibration” of strategy. For the survey's highest-ranked firm, for example, an almost 6 percent increase in head count followed nary a merger or acquisition. Another firm, with three small acquisitions, saw its head count decline—part of a deliberate reshaping.

Read our overview of the NLJ 500 rankings, and explore the charts and lively infographics for firm breakdowns on partners, largest offices and growth shifts from 2015. In the coming days, walk through the Top 5 cities by lawyer counts, and read our annual Women in Law Scorecard, which ranks firms on gender diversity, with special emphasis on women in partnership positions.