HathiTrust (pronounced hah-tee) is a "collaborative of academic and research libraries preserving 17+ million digitized items." This organization provides reading access to a digital archive of books, journals and government documents -- called HathiTrust Digital Library -- many of which are in the public domain (available for full view).
There are multiple paths to find HathiTrust Digital Library items:
The U-M Library is a partner in the HathiTrust Digital Library organization, which means that the U-M community has additional access benefits, with a valid login (U-M uniqname and password). Click on the yellow LOG IN button near the top of the home page. At the "Find your partner institution" pop-up, select the "University of Michigan" and click on the yellow CONTINUE button.