Book excerpt: This title is published in Open Access with the support of the University of Helsinki Library. This book takes a long-run view of the global maritime trade of Boston, New York, and Philadelphia from 1700 to American Independence in 1776. Land argues that the three cities developed large, global networks of maritime commerce and exchange that created tension between merchants and the British Empire which sought to enforce mercantilist policies to constrain American trade to within the British Empire. Colonial merchants created and then expanded their mercantile networks well beyond the confines of the British Empire. This trans-imperial trade (often considered smuggling by British authorities) formed the roots of what became known as the American Revolution.