Open Library

One of the most important research tool I have discovered recently is "Open Library". It is thanks to that tool that I was finally able to locate not just one buth three photos of the elusive William Banks Levy (in low resolution unfortunately), and that I was finally able to confirm the exact date at which Kay Kamen's nephew, George, was sent to Europe to take over from Bill Levy, etc.

The search engine is a pain in the neck, but regardless, it remains a very powerful tool once you get the hang of it.