This review essay asks: What do we know about law firms? In reviewing over 40 years of empirical research, we find that life as an attorney has changed. Big firm life, once genteel, lucrative, and leisurely (at least for those who could get past the discriminatory entry barriers), is now more competitive. Today, clients tend to treat legal services like any other input, demanding that lawyers justify their bills and compete for the business. To remain profitable, big law firms recruit rainmakers from other firms. Partners who don't bring in business are relegated to secondary status or forced out of the firm altogether. The research also suggests that associates are dissatisfied with law firm life, specifically the billable hour demands. At the same time, the best law students from the best schools continue to flock to the big firms, willing to work tremendous hours in return for compensation in excess of most federal judges. Small firm life has changed less. For these lawyers, life has always been a struggle to survive. They continue to hunt for work. They draft wills, advise small businesses, and help people navigate the civil and criminal legal systems. They navigate the professional rules they see as promulgated by elite-firm lawyers. But in spite of all these obstacles, and as big-firm lawyers spend more of their time watching their backs, contemporary solo and small-firm lawyers - the ones who have been studied, in any event - derive community and support from lawyers down the hall or across town. And, as big-firm lawyers come increasingly under the control of their corporate clients, the small-practice lawyer remains his or her own boss. Studies of in-house lawyers yield the most surprising results. These lawyers do interesting work, get paid well, and avoid the unpredictable workloads associated with the large firm. Perhaps most importantly, in-house lawyers do not have to pound the pavement in search of clients. Much of the debate in the last 40 years surrounding changes in small and big law firms seems to come together under the heading of professionalism. Confounding the predictions that would have been made in the 1960s, big firm lawyers emerge as the pawns of market forces, their professionalism a casualty of their desperate and sometimes puzzling responses to those market forces. Small-practice lawyers, by contrast, have found new ways to create professional communities as they cling to survival in what has always been a difficult economic environment.