The project started around 2003 when Google approached the Library of Congress with proposal to digitize all the books in the library. When the Library of Congress offered a counterproposal that would only include public domain books, Google did not follow up.
Google then turned other major libraries including those at the University of Michigan, Oxford University and Harvard University and the New York Public Library with some success.
The Google Library Project began in 2004 with the announcement that to would be digitizing the collections of five major university libraries. which would cover more than 15 million volumes.
It is an amazing resources and the good of using Google books that it can help educators assess the content of a book for its relation to the topic, readability level and to teach students about public domain materials and copyright laws.
Google Books has provided scholars the ability to engage on primary research in a way that did not exist till now. Google Books has taken some limitations such as lack of funding, travelling and research at various location by scanning historical documents that would have been difficult to obtain through traditional modes.
Google Books Project