Carl Sandburg books in order
8 books in the catalogue, about 141 hours of reading in all; the shortest takes 4 hours and the longest 27 hours.
1 series and 7 standalone books in the catalogue.
Rootabaga
2 books
Rootabaga Stories 4.1 h Rootabaga Pigeons length not known
Standalone books
Abraham Lincoln 11.7 h 
The United States in Literature [with Three Long Stories] -- Seventh Edition 15.0 h 
Prentice Hall Literature -- Platinum 27.3 h 
Prentice Hall Literature--Timeless Voices, Timeless Themes--The American Experience 22.5 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 
Prentice Hall Literature 21.3 h