John Herndon "Johnny" Mercer (1909–76) remained in the forefront of American popular music from the 1930s through the 1960s, writing over a thousand songs, collaborating with all the great popular composers and jazz musicians of his day, working in Hollywood and on Broadway, and as cofounder of Capitol Records, helping to promote the careers of Nat "King" Cole, Margaret Whiting, Peggy Lee, and many other singers. Mercer's songs—sung by Bing Crosby, Billie Holiday, Judy Garland, Frank Sinatra, Ella Fitzgerald, Tony Bennett, Lena Horne, and scores of other performers—are canonical parts of the great American songbook. Four of his songs received Academy Awards: "Moon River," "Days of Wine and Roses," "On the Atchison, Topeka, and the Santa Fe," and "In the Cool, Cool, Cool of the Evening." Mercer standards such as "Hooray for Hollywood" and "You Must Have Been a Beautiful Baby" remain in the popular imagination.

Exhaustively researched, Glenn T. Eskew's biography improves upon earlier popular treatments of the Savannah, Georgia–born songwriter to produce a sophisticated, insightful, evenhanded examination of one of America's most popular and successful chart-toppers. Johnny Mercer: Southern Songwriter for the World provides a compelling chronological narrative that places Mercer within a larger framework of diaspora entertainers who spread a southern multiracial culture across the nation and around the world. Eskew contends that Mercer and much of his music remained rooted in his native South, being deeply influenced by the folk music of coastal Georgia and the blues and jazz recordings made by black and white musicians. At Capitol Records, Mercer helped redirect American popular music by commodifying these formerly distinctive regional sounds into popular music. When rock 'n' roll diminished opportunities at home, Mercer looked abroad, collaborating with international composers to create transnational songs.

At heart, Eskew says, Mercer was a jazz musician rather than a Tin Pan Alley lyricist, and the interpenetration of jazz and popular song that he created expressed elements of his southern heritage that made his work distinctive and consistently kept his music before an approving audience.