You’re looking at the City Hall, built in 1873, designed by Franklin Long. The Tribune newspaper also occupied the building, which must have made it easy for the boys to get a quote from whatever official wandered in that day.
This was heart of the city - for a while. Minneapolis grew up along the river, spreading down Washington as well as out along the avenues Hennepin and Nicollet. This was where the three prime streets met. Not exactly Times Square, but for a few decades it was the heart of town. Bridge Square.
Minneapolis wasn’t built in a day; it took at least a week to string that many wires.
On the left, a shot of the Temple Court building (1886) in the distance, with the Boston Block (I think) under construction. Larry Millett's "Lost Twin Cities" says the Boston Block was built in 1881 but rebuilt in 1887, so that's possibly the date of the photo.