Nonetheless, my point is that a Google search will provide sources from which the original source can be discovered. It is not possible to "prove" that all original sources are true, simply because they are not. Participants often lied or misrepresented "facts" in a self-serving manner.
Agree with chellers. The closer you get to the source, the better. I hate it when there's no footnotes or endnotes. I hate the modern style of having one endnote for the paragraph with multiple references. You have to figure out which one is the relevant one.
The overarching point it that Foote's narrative will live long after the academic experts of his era are as forgotten as James Ford Rhodes. Catton is a similar example, but not nearly as good.