You're unlikely to find a satisfying, one-volume treatment of this subject. Trust me, I've tried.

Why? Mostly because there are so many differing points of view at play. Some authors see the fall of labor as a result of state action. Some see it as a lack of true radicalism. Some see it as a result of there being no widespread acceptance of an American 'proletariat.'And some see it as a result of American individualism -- a myth perhaps (in some eyes,) -- that dissuades collective action. And there are many other, much more nuanced views. They are all wrong. And they are all correct. It all depends on specific historical context. What happened in, for example, Chicago in 1920 is vastly different than what happened in 1880 Oregon. Ergo, no one good volume on the subject. So rather than one authoritative Big Important Book, There are numerous excellent studies on various regions and industries. To wit (and in no particular order:)

Cohen, Making a New Deal

Fink, Workingman's Democracy

Gerstle, Working-Class Americanism

Greene, Pure and Simple Politics

Montgomery, The Fall of the House of Labor

Lichtenstein, Walter Reuther: The Most Dangerous Man in Detroit (One of my personal favorite books. A really well-done biography of both Reuther and the UAW)

Letwin, The Challenge of Interracial Unionism

Stansell, City of Women

Sugrue, The origins of the Urban Crisis

Gutman, Work, Culture and Society

Richards, Union-Free America

Fraser and Gerstle, eds, The Rise and Fall of the New Deal Order