The uniqueness of Samuel Wilson, Jr.’s (born 1911) career is studied in terms of practicing architect, scholar, and civic leader. The author was motived by the void in architectural literature about the people who have saved our architectural heritage. The introduction explains the purpose of the dissertation to determine, analyse, and interpret Wilson’s contributions, beginning in 1934. The search began with oral histories taken from Wilson and some of his peers. Archival research was conducted in the Tulane University Library and The Historic New Orleans Collection. Chapter 1 gives biographical information on Wilson, and background on New Orleans and the Vieux Carré (French Quarter) in the 1920s when Wilson entered Tulane University (1927). Nathaniel Cortlandt Curtis [Sr.], Moise Goldstein, and Richard Koch, the trio of architects who influenced Wilson, are introduced. Chapter 2 is devoted to the experiences that moved Wilson in the direction of historic buildings, the Historic American Buildings Survey (1934) and a scholarship to Europe (1938). Chapter 3 presents Wilson’s mentor, Richard Koch, a pioneer in adaptive reuse and new design in an historic environment. Wilson carried his mentor’s concepts further and into the realm of scholarly pursuit. Along with publishing and teaching, Wilson was a driving force in the institutionalization of preservation in New Orleans. His election as founding president of Louisiana Landmarks Society (1950) is the beginning of his leadership role for the next twenty years. Chapter 4 deals with Wilson’s projects in the post World War II era of new construction in the Vieux Carré and central city, and how he guided change by the use of historicism. Chapter 5 discusses, through Wilson’s projects, the critical preservation issues of the 1950s and 1960s. It was an era of problem solving without precedent guidelines. Chapter 6 summarizes Wilson’s contributions from his field accomplishments and the creation of a new body of knowledge to his activities in national preservation policy. The appendixes form a catalog of Wilson’s work: historic projects; literary works; drawings; TV programs, audio and audio—visual recordings; honors and awards; translation of a specification for a colonial horse-and-wind mill; and four walking tours. There are 154 illustrations. / Ph. D.