Walt Whitman books in order
7 books in the catalogue, about 107 hours of reading in all; the shortest takes 6 hours and the longest 23 hours.
7 standalone books in the catalogue.
Standalone books
Leaves of Grass 7.0 h 
The United States in Literature [with Three Long Stories] -- Seventh Edition 15.0 h 
Prentice Hall Literature--Timeless Voices, Timeless Themes--The American Experience 22.5 h 
Prentice Hall Literature--Timeless Voices, Timeless Themes--Copper Level 6.2 h 
Prentice Hall Literature--Timeless Voices, Timeless Themes--Gold Level 19.8 h Prentice Hall Literature--Timeless Voices, Timeless Themes--Silver Level 18.7 h 
American Earth 17.9 h