In chapters XIII-XV of Hamlin Garland’s Boy Life on the Prairie (Nebraska, 1961) the stacking of wheat is explained in enough detail for the book to be usable as an instruction manual, and he also describes the various technical changes wheat harvesting went through during his lifetime. (From when I was about six I just barely remember the kind of crew-operated threshing machine that left a big pile of chaff; it had replaced hand stacking and would soon be replaced by the combine). Stacking wheat was a difficult and critical job, and good stackers were in high demand during the harvest season, though not really afterwards, since they were just farmworkers after all.
Things were about the same in France:
My father would contract to cut certain fields of rye or oats, the only grains grown in our area at that time. When the grain was brought in, my father was much in demand for that particular job, setting the sheaves up in rounded stacks called groac’hel. He was a past master in the art of constructing such stacks. Stacks had to be very well built; because the winnowing was done entirely by flail, it took a long time, and if during that time it should rain heavily on poorly constructed stacks, the water would get inside and everything would be ruined, grain and straw.
Memoirs of a Breton Peasant, Jean-Marie DeGuignet, Seven Stories Press, 2004
Stacks were stacked out in the field, though, not in Chicago. I don’t know where Sandburg got this from:
Hog Butcher for the World,
Tool Maker, Stacker of Wheat,
Player with Railroads and the Nation’s Freight Handler;
Stormy, husky, brawling,
City of the Big Shoulders….
In the high and far-off times they even stacked things in New England. Maybe they still do sometimes, at re-enactments and the like:
“But most of all
He thinks if he could have another chance
To teach him how to build a load of hay”
“I know, that’s Silas’ one accomplishment.
He bundles every forkful in its place,
And tags and numbers it for future reference,
So he can find and easily dislodge it
In the unloading. Silas does that well.
He takes it out in bunches like big birds’ nests.
You never see him standing on the hay
He’s trying to lift, straining to lift himself.”
Arthur Rimbaud left the difficult job to his mom:
Delahaye was slightly awed when he called at the farm… He found his friend at harvest-time, rhythmically heaving the sheaves of wheat overhead to his mother, who formed the haystack.
Rimbaud, Graham Robb, Picador, 2000, p. 301.
During his time in the U.S. the great Norwegian author and quisling Knut Hamsun worked the wheat harvest on a plantation-style bonanza farm in North Dakota and warned against the 15-hour days there. Whether he actually stacked wheat is unknown.