I'm not sure what you mean by "stand up today." Churchill is a talented writer and his works remain entertaining today. I'm guessing you are referring to his works as history, not as entertainment though. Having read his four volume A History of the English Speaking Peoples, I'll answer with an analysis of that series. I have not read his other works, such as his histories of the world wars or his biography of his ancestor John Churchill. If those books are markedly different, I'd welcome someone pointing that out.
To begin with Churchill is not an academic, he is a popular historian. Like modern popular historians, he is more concerned with keeping his writing entertaining, than in digging down into the nitty gritty of everyday life. Churchill writes mostly about the actions of great men and women and credits them with moving forward different historical events.
For example his sections on the wars of succession in England from the reigns of Richard II to Henry VII, focuses almost entirely on the actions of the king. To Churchill the problems began with Richard II's inability to get along with courtiers and ended decades later due to Henry VII's political genius.
When Churchill does switch to social or economic history, it generally remains dominated by the actions of great men. For example in discussing the formation of the First English Parliament, Churchill talks mostly about the relationship between Simon de Montfort and King Henry III.
In the later books when he hits early modern times, Churchill begins to talk a little bit about the actions of communities instead of individuals. For example he spends a decent amount of time on Charterism and the reforms to the election system in the 19th century. Still when he turns to the American Civil War, he is back to discussing the actions of great men, he portrays the war as a struggle between the genius of the northern and southern generals.
At various points Churchill becomes "chatty," and can't seem to help inserting himself into some kind of historical debate. He devotes a section to arguing why he believes Richard III ordered the death of the Princes in the Tower, stepping in to defend the honor of Henry VII against any suggestion the later king might have ordered the murders. Churchill likewise does not bother to hid his sympathies for the monarchists in the English Civil War.
Churchill also loves the kind of anecdotes that remain popular in modern popular histories. For example he tells the story of how Alfred the Great was inspired to continue fighting the Norse, by the tenacity of a spider attempting to spin a web between a table and the wall.
Churchill's writing is dominated by the ideologies of the late 19th century. Churchill firmly believes in Whig History and the special destinies of certain peoples and societies. Churchill believes that the English Speaking Peoples (mostly the Americans and the British) have a special place in the world.
Which brings us to a very awkward point. Churchill is an imperialist and holds views that are very racist. Churchill writes about how slavery was an improvement over life in Africa and venerates the "civilizing power" of white imperialism. You will not find any acknowledgement of the horrors of the British Empire in this work. Likewise Churchill believes the struggles of the twentieth century can be considered a struggle between the Teutonic Peoples and the English Speaking Peoples.
Finally we come to the question of "accuracy." I am woefully unable to comment on much of the series' British history, having not read enough other British history to render a trustworthy opinion. I can however speak about his history of the American Civil War.
Churchill's opinions about the American Civil War are out of date with the modern historiography of that conflict. Churchill is if not a believer in Lost Cause mythology, at least a fellow traveler. He downplays the horrors of slavery, champions southern virtue and denigrates the character of U.S. Grant.
For Churchill the struggle was about Southern heroism holding off the North until the remorseless willingness of northern leaders to throw away their soldiers lives overcame and oppressed the South. This is not the modern viewpoint even in popular history.
To summarize, Churchill is a talented writer, but he is not an academic historian. His work is filled with the racist ideologies that he grew up in as a member of the British upper class of the late 19th/early 20th century.
Dear readers, if you can't say anything about the historical works Churchill wrote - and he did write them - please don't post. Furthermore, if you can say something, it should be of a higher quality than what Churchill wrote in-depth and comprehensive.
If in an in-depth and comprehensive answer on Churchill's writing you can say something about how literal the apocryphal quote should be taken, that's awesome. If all you can say is that an apocryphal quote is a riff off the famous saying "history is written by the victors", then you will not emerge victorious in the battle with our 'remove' button.
Thanks.
I think History has been kinder to Churchill than it would have been had he not written it. That's not to say that it's the job of history to be kind or unkind, and there are certainly decisions of his or aspects of his character that are judged poorly. But I think his writing of these histories has had an enduring impact on the historiography of the matters at hand. Unfortunately it's a bit of a counterfactual, because we're contemplating what History would have been like had he not written it.
That being said, I'll give you two examples that I'm familiar with from The World Crisis that I think make the point. NB: I've only listened to this as the 50-hour "abridged" audiobook so I may be being unfair to how he writes in the unabridged volumes, but I suspect not.
The two examples I can touch on, for which his conduct has otherwise garnered historical criticism, are:
Now, in the first point, to my knowledge, Churchill's writings, based purely on the logic of his argument rather than any historical or documentary evidence supporting him, was that because the Ottomans entered the war on the German side, that he was of course justified in withholding the ships. His argument begs the question, because he assumes that had the ships been handed over, the Ottomans still would have declared war, rather than, say, having a change of heart. But it also can't be ignored, because despite being a counterfactual it's not an implausible counterfactual. But in terms of your question, I'm not sure it's a counterfactual that would have been made had he not made it himself. He references contemporary criticism of the decision in The World Crisis and dismisses it on that basis. The result is that while the incident features in analysis of Ottoman reasons for entering the war, I think it's less prominent than it might otherwise have been.
On Gallipoli I think is one area where History will be kinder to him the further on we go. I'm not as familiar with how Churchill's role at Gallipoli is viewed in the collective memory of the ANZACs (I believe we had an AMA recently that, had I thought of it, this might have been a good question) but the more that memory of non-Western front experiences in WWI recedes, and the meatgrinder narrative of the Western front increases by comparison, I think the strategic logic of Churchill's arguments about Gallipoli (and the "Easterners" generally) will become more powerful to History. Not to mention that with hindsight, while certainly not being absolved from responsibility it's clear that he was made into a bit of a political scapegoat when, say, Kitchener had the greater authority.
In discussing Gallipoli, Churchill is memoirist, apologist, and military analyst all at once. I'm less familiar with the historiography of how accurate Churchill's account of the strategic planning may be, or how realistic his alternative scenarios were regarded by the military commanders at the time (my own view is that the British systematically underestimated the Ottomans, so I'm not sure how much to credit alternative British analysis anyways), but in any event the account is a powerful self-defense.
As I mentioned I suspect that defense will be increasingly successful. But I think it's also one very good example of where History has been kind to him, as he says, because he wrote it. While it's possible some other historian might have eventually come to his defense, his writing a defense of himself in one of the most popular histories of that war I think has resulted in History being kinder to him than it otherwise would have been.
Here's a good example that takes Churchill's side uncrictically of both incidents from a Telegraph article written by a Churchill historian. I found it after I did my write up, but it actually could not be a more perfect example of what I'm talking about and deals pretty much exclusively with the two issues I discussed. NB how he takes Churchill's line on the timing of the ship transfer, implying that the Ottomans had already decided to side with Germany when actually they signed the treaty the day after the seizure, and so on: http://www.telegraph.co.uk/history/world-war-one/11561066/Gallipoli-was-Churchills-folly-but-not-only-his.html
Churchill exploited his position by sharing information in his written works about WW2 that others were prohibited from divulging. As a result, many of his works on the subject were the first to share certain details, and this gave him the opportunity to shape perceptions of the conflict and his involvement in it.
Though they are informative and very entertaining, those works are quite clearly written by someone who has an extraordinarily high opinion of himself, and are thus tainted by vanity. Other authors that followed tend to cast him in a much less favourable light, and assign him much less responsibility for the eventual allied victory. He was also much less popular among the British public than his accounts tend to suggest.
It should also be mentioned that Churchill was almost certainly an alcoholic, which may have contributed to his rose coloured rememberings. His alcohol use remains a controversial issue, but in my opinion, there is more than enough evidence to conclude that he was a long term problem drinker.
His work on the world wars can be useful in certain circumstances particularly The Second World War Volumes.
Firstly they can be used to gauge his views on certain situations (though they were written after the war so caution is advised, you would probably need to cooberate with other sources)
Churchill was pretty lax when it came to things like state secrets and some of the material discussed in the work was not available to contemporary historians (what the situation is now idk, but a lot of WW2 documents are now open)
Works like the River War, the Story of the Malakand Field Force, Boer war ect. are very useful primary sources to historians particularly those studying late Victorian popular culture and attitudes (NOT students of military history)
I'd just like to comment that the actual quote is:
"For my part, I consider that it will be found much better by all Parties to leave the past to history, especially as I propose to write that history." - Speech in the House of Commons January 23, 1948