Clarification (2019-03-01): The fiscal years in the story and charts below refer to the year the data were published by The American Lawyer and The National Law Journal. Those figures pertain to the prior fiscal year for the firms included in Am Law 200 and NLJ 500 indexes.

For several years Boston has been seen as a go-to destination for many Big Law firms, and a new analysis by The American Lawyer shows that the expansion effort has been led by Am Law 200 firms looking to establish a foothold in Beantown.

Since 2013, the total number of Am Law 200-ranked firms with at least one office in the Boston metro area has increased by more than 16 percent — or eight firms — according to an analysis of 2013-2018 data from ALM Intellligence's Legal Compass. By contrast, at either end of the same five-year span, the number of National Law Journal 350 index-ranked firms was static at 12.

Five years ago, there were 49 Am Law 200 firms with offices in the Boston metro; the number remained fairly constant until 2016, when the city started experiencing a Big Law boom.

In May 2017, Kirkland & Ellis opened an office in the city's Bay Back neighborhood. Hogan Lovells followed suit, merging with local litigation boutique Collora. Womble Bond Dickinson opened an office with a trio of McCarter & English IP partners. In 2018, Quinn Emanuel Urquhart & Sullivan opened an office in Boston with three of its IP litigators, while Washington, D.C.-based Arent Fox merged with local 55-lawyer firm Posternak Blankstein & Lund.

By the end of 2018, the city boasted 57 Am Law 200 ranked firms.

The rate of growth is similar to that in other markets, like Houston and Philadelphia, which have also experienced an uptick in the number of Am Law 200 firms since 2013.

Despite the entrance of out of town firms into the legal market, firms with Boston roots still have the largest arsenal of Big Law talent.

Goodwin Procter, which was founded in Boston in 1912, boasts the most partners of any Am Law 200 firm in the Boston metro area with 151 partners. Ropes & Gray, one of the first law firms founded in the city, had the second largest, with 121 partners. While Mintz, Levin, Cohn, Ferris, Glovsky and Popeo was a close third with 120 partners.