How did Carl Sandburg's background and era influence his poem "Chicago"?

Carl Sandburg was the perfect poet to write a poem about the city of Chicago in 1914.  Sandburg, in fact, did write a now-classic poem about Chicago in that year.

Sandburg grew up in Illinois, the same state in which Chicago is located, and was living in Chicago when he wrote the "Chicago" poem.

"Chicago" describes some of the acitvities that kept people busy in the Windy City.  Some of them are: hog butcher, tool maker, "player with railroads," brawling, singing, "piling job on job," "Shoveling, Wrecking, Planning, Building."

These activities bear many similarites to Sandburg's own personal activities: among his jobs were newsboy, milkman, bottle washer, icehouse worker, carpenter, and soldier.  During a period as a hobo hitching rides on trains, his jaw was broken by a punch from a railroad brakeman.  Later in life, Sandburg became an expert collector and singer of American folk songs.

"Chicago" also describes some of the cruel aspects of life in Chicago:

I 
have seen your painted women under the gas lamps 
luring the farm boys. 
And they tell me you are crooked and I answer: Yes, it 
is true I have seen the gunman kill and go free to 
kill again. 
And they tell me you are brutal and my reply is: On the 
faces of women and children I have seen the marks 
of wanton hunger.

These are things that Sandburg surely would have seen during his years of drifting.

In 1914, when Sandburg wrote the poem, the city of Chicago was undergoing a period of rapid industrial growth.  The poem describes this growth, and also mentions the social ills that accompanied it, and that were allowed to  continue with minimal interference from government.