This book develops a comprehensive analysis of contemporary regionalism in the Americas, which the authors characterise as Liquid Regionalism, given its unstable, flexible and loose characteristics. It innovates by introducing a new concept to assess regional initiatives in the American continents, contributing to Latin American and comparative regionalism research agendas. The book analyses major regional projects in the Americas and develops these into a novel typology of consultation, cooperation and integration. This typology helps explain the level of commitments and institutional depth of regional initiatives across the continent. The book is for scholars, postgraduate and undergraduate students interested in the regional and political dynamics of the Americas across the social sciences, including international relations, political science, sociology, international political economy, international trade, and history.