5. The disaster of 1816 unfolded slowly, though scientists had been aware of cooling trends for a decade
The second decade of the 19th century was the coldest in the recorded history of North America, the continuation of a trend which is now identified as the end of the period known as the Little Ice Age. Fed by numerous volcanic eruptions which clouded the atmosphere, the cooling was noticeable (as noted above, Jefferson was one proponent of ongoing climate change at the time) but not as yet catastrophic. The massive Tambora eruption added to the cooling effect of atmospheric particulates, greatly amplifying the cooling for the growing season in 1816. Farmers, then and now, are entirely reliant on the weather for successful crops. In 1816 the majority of crops around the world were grown on small farms, by farmers of little education beyond that needed to toil in the earth. Weather patterns were predicted largely based on folklore.
By the time farmers realized that their output for the year would be minimal, it was far too late to do anything about it, though there had been little they could have done anyway. Winter wheat crops could have thrived in some areas, and in some they did, but oats – vital to the economy in many ways – did not. Oats were needed not only for human consumption, but as fodder for the animals which provided the motive power for plows and wagons. Animals moved products to market in the cities, or to the rivers and streams which carried them to the warehouses. Farmers who relied on cash crops other than foodstuffs, largely cotton, tobacco, and indigo, found their livelihoods threatened as well. For example, a May cold front brought killing frost as far south as Tennessee, destroying the cotton crops. Farmers who had already planted their corn and wheat were forced to plow up the dead and damaged plants and start over, secure in the knowledge acquired from years of experience that warmer weather was coming. They were wrong.