You run a farm in northern Vermont that raises turkeys. You can get a decent price for your birds by selling them locally but a much better price and can sell many more if you take them to the folk in Boston. There are no trucks to speak of, as they haven't been invented yet, so you gotta walk the 200 miles with such a boisterous load. There's no ice block big enough to keep your birds cold for that long of a journey and if there was, you couldn't pull it. The birds gotta get there alive, and they can only do 10 - 12 miles a day. You get a few neighboring farms to come with so you can watch each-other's birds and have some company on the 3 week on the road. Along the way you loose about 10% of your flock to foxes, rivers, robbers, and your own hunger. You arrive in Boston and get a fair price for your troubles, just enough to make the trip worth it. You spend a few days getting back to Vermont and by the time you get back it'll have been about a month on the road. You settle in for a rough winter. You're gonna do it all again next year. At least there's plenty of maple syrup.