This book examines a seminal 1964 Dan Flavin exhibition at New York's influential (though short-lived) Green Gallery, which broke new ground--and marked a turning-point in the artist's career--with the first series of works composed of colored fluorescent light tubes. The exhibition included seminal works like "the diagonal of May 25, 1963 (to Robert Rosenblum)" (1963) and "a primary picture" (1964). This volume coincides with Zwirner and Wirth's recreation of the Green Gallery installation--the first in a series of projects that will explore the presentation and influence of historical gallery shows of the twentieth century. Along with new scholarship by Jeffrey Weiss, former Director of the Dia Art Foundation, this volume contains new color plates, a selection of drawings tracing the development of Flavin's ideas about these works and their original installation, rare archival photographs, reproductions of exhibition reviews and a selection of recently commissioned statements by artists and critics who saw the exhibition.