o show the public its captive audience was also a productive one, Minnesota’s Stillwater Prison built an exhibit made of twine for the 1936 state fair. Like many other states, Minnesota used convicts to produce products for the Industrial Revolution — such as twine. When the horse-drawn McCormick harvester and twine binder debuted in 1881, it eliminated thousands of farm workers, but increased the need for a material to tie the millions of hay bales it harvested. By 1892, the Stillwater prisoners produced 1 million tons of twine a year, enough to pay for the entire prison’s annual budget.