I wrote back to him that if he was thinking of writing more, I'd love a musing on when "enough is enough." He asked for clarification and got this essay in return, which I thought I'd cross-post here as it's applicable.
So here's what I'm grappling with at the moment.
I'm working on researching the history of the first Morgan horse, a stallion named Figure. There have been sketchy histories done of him in the past, but nothing substantive, with true primary source research.
Figure was in Vermont from approximately 1792 - 1819. He had upwards of a dozen owners during that time, in over half a dozen distinct different parts of the state.
I have in my mind the idea to go to each of the places where we know Figure was and look for journals, diaries, and letters dated within a few years of that time, and read through them ALL to see if any mention this strange horse. I could also do the same for newspaper accounts during his lifetime.
Even more specifically, there's a story that in 1817, when James Monroe visited Vermont as part of his Era of Good Feelings tour, he rode Figure in a parade in Montpelier. There's one published source about the visit; it doesn't mention the horse. But surely there are letters, diaries, etc., remembering the president's visit to Vermont. Would one of them be the original source for this story? Would one of them have mentioned that the president was given Justin Morgan's horse to ride? Those accounts could potentially be located all over the state.
Is it worth it to read every single word? Is it worth it to track down every source that could possibly have bearing on the topic you're researching, especially when it's statewide? Or do you hit a tipping point when you have enough evidence to support your thesis and tell your story and doing even more research than that clutters it? Is it just fun to read 8 million things even if they don't necessarily have strict bearing on it?
I think that this problem becomes more seductive the more you know and understand about history and good primary source research. As you learn to do a close reading of the sources you see how themes can track through contemporary accounts that might not even have anything to do with your primary subject. (Would a farmer's account of how he uses his workhorses be useful to illustrate the world that Figure lived in? Would 10 farmers accounts yield a sort of average lived experience for a workhorse in Vermont? How about reading 100 accounts in order to find the perfect encapsulating quote?)
So, when do you draw that line without going completely insane/wasting your time/never finishing your project?