If you read The Long Winter, Laura Ingalls Wilder's novel about narrowly avoiding starving to death during a ferocious winter on the South Dakota prairie, then you'll remember how the trains stopped running because of the snowfall. In fact, that's a big part of why Laura and her family were so hungry — their harvest had been lean and the train carried the supplies they were dependent upon.
I'd never had a real clear idea of what "the train can't get through" really meant, not being totally clear on how to adjust snow-clearing expectations from today back to the 1880s. But, as it turns out, when the train company said they couldn't get the trains through, they were not messing around. The above image, from the Minnesota Historical Society, shows you the kind of snowfall we're talking about. That picture was taken in southern Minnesota, during the same winter — 1880-1881 — that nearly killed Laura Ingalls Wilder. Please note the dude standing on top of the train. He really gives you the overwhelming sense of scale.
Last year, Barbara Mayes-Boustead, a meteorologist with the National Weather Service, actually looked at the records we have for temperatures and snowfall from that winter, most of which come from military forts and major cities miles away from the small town of DeSmet, where Laura Ingalls Wilder lived. Mayes-Boustead found that the story in the book matches up reasonably accurately with actual data.
She's got a series of short audio commentaries on the winter of 1880-1881 and how it plays out in the Little House books, including a really fascinating one about the climate patterns and probably created those many months of blizzards. By looking at weather patterns from the time and at the climate systems we associate with weather like that today, Mayes-Boustead says that we can probably blame the Long Winter on a combination of a strong negative North Atlantic Oscillation — a pattern in the jet stream that sucks icy air from the Arctic down into the Midwestern US — and an El Nino year — which tends to make that same region of the county wetter than usual.