Thanks to Nick, I now know that Mississippi State University has made the Papers of Ulysses S. Grant available online. Check it out here. Given the current focus of my studies I probably won’t find a need to go there often, but I’m sure I’ll want to, and as a result will find myself sucked in. I think you get a different picture of Grant when you read what he wrote before and during the war as opposed to what he wrote in his memoirs. But that’s just me – your mileage may vary.