A question which occurred to me: which President do we have the most confirmable information about, such as the most documents?
I imagine it’s someone in the modern age, where documentation and recording are mandated and easier to accomplish, so maybe someone like Nixon? Whereas earlier Presidents we know less about, because they either had their papers destroyed (Buchanan) or they themselves altered them (Madison).
That's an interesting question. You make a good point about it probably being a modern President, particularly one whose personal and official papers were carefully preserved and archived in a Presidential Library. When it comes to official records and correspondence from a President's time in office, LBJ, Clinton, George W. Bush, and Obama were especially careful with preserving EVERYTHING that went on in their White Houses. Nixon, too, to a certain extent and Nixon's personal notes and planning memos are particularly revealing, but with Nixon, you never know what he didn't share or what he may have destroyed. With LBJ and Nixon you also have extensive recordings of phone calls and Nixon's taping systems, which allow us to hear Presidents at work in ways that we don't normally get to see them, warts and all (expletives not deleted).
But it really depends on what kind of information you're looking for. Because if it's personal, biographical information, that is different. John Quincy Adams kept a detailed diary that recorded virtually everything he did, what he thought, and what he felt about others and pretty much never missed a day for 70 years. I don't think there's any President whose day-by-day lives were so intimately logged as JQA. The diaries of Rutherford B. Hayes and James A. Garfield are also very interesting, but far less extensive than JQA's (plus, Garfield was only 49 years old when he died). Jimmy Carter and Ronald Reagan kept pretty detailed daily diaries during their Presidencies -- and Reagan was a shockingly talented writer despite what many people often think about him being an "amiable dunce".
An interesting possibility in the future is George H.W. Bush. Jon Meacham's 2015 biography of Bush, Destiny and Power: The American Odyssey of George Herbert Walker Bush (BOOK | KINDLE | AUDIO) is, in my opinion, perhaps the best single-volume biography ever written about an American President. Meacham had extraordinary access to Bush, his family, his friends, his papers, everything. But when you read the book, you also learn that Meacham drew a lot from Bush's diaries, to which he had full access. Apparently, Bush kept an extensive daily diary that he started when he joined the U.S. Navy at the age of 18 in World War II and maintained for nearly 60 years. Bush's wife, Barbara, also kept a detailed diary (which Meacham also had access to for his book), and the Bushes -- especially the 41st President -- were big letter-writers throughout their lives. So, if and when all that material is available for researchers it's going to put Bush up near the top of the list when it comes to having the most letters, diaries, and detailed information on day-to-day activities documenting any President's entire life.














