The Internet Archive has found a loophole in the most recent copyright act that makes it possible for libraries to digitize more books. It has been thought that only books copyrighted before 1923 could freely be digitized by libraries. Internet Archive found that section 108h allows libraries to scan and make available books published 1923 to 1941 if they are not being actively sold. Currently they only have 61 titles available in the collection that they named for Sonny Bono.
In the long run this will be helpful in genealogy as more titles will become available online. Doing a search for “genealogy” on Internet Archive gives over 130,000 books. That doesn’t include things like the US census records which they have available for free.