This collection of sixteen comparative essays, plus an introduction and a conclusion, marks a significant step in the advancement of labor history on both sides of the Pacific Ocean. Resulting as it does from an incipient discussion at a 2013 labor history conference in New York City and a 2015 panel presentation at a conference in Sydney, Frontiers of Labor reveals the value of continuing collaboration. Presenting these essays under six topic headings, however, seems to mimic the setup of a conference panel rather than organization for publication. The first subheading, “The Great War: Repression and Political Countermobilization,” encompasses four essays. Other topical subdivisions contain two or three essays each, covering labor coercion, Irish ethnicity, collective action and regulation, labor institutions, and transnational politics. Chronologically scattered, most of the essays focus on the late nineteenth and early twentieth centuries, but the earliest and latest are grouped together under “Varieties of Labor Coercion,” with one comparing convict indenture in colonial America and in early Australia and the other analyzing union-avoidance strategies in meat industries from the 1980s into the early twenty-first century. All essays—except one, which also includes New Zealand—conform to the binational comparative approach.