It's pretty obscure, given the magnitude of lives lost, the number of buildings torched, and acres burned. Fire was quite common then. People burned to clear acreage for farming, etc. No one ever bothered to put out the fires, so they smoldered until winter came. Like any fire, if a hot ember hit a fuel "jackpot" on a hot, dry day, the fire could jump to life. Throw in wind and it can be off to the races even in flat terrain. 

In the realm of wildland fire, one hears much more about the Big Blowup of 1910 in Montana and Idaho. That fire made heroes of people like Ed Pulaski (inventer of the ubiquitous and eponymous fireline tool), and, excused the expression, sparked big changes in federal land use and protection policies.