"This compilation provides access to much of the documentary legacy remaining from the railroad companies. By identifying what exists and where it can be found, Barnett's book will open doors to information about these transportation lines in Michigan. The sources revealed ... provide abundant evidence on the operations of railroads, describe the areas served by them, and show how such firms helped to develop the Great Lakes State."--Introduction p. xvi.

1921-1942 contain abstracts of periodical reports.