The retaining wall at left is the side of a city street. When downtown was raised, the city decided to pay for the cost of elevating the streets, and that raising the adjacent sidewalks should be paid for be the roadside business owners, who balked.
Therefore, the steets were raised, and the sidewalks remained between 8 and 35 feet below them, leading to falling pedestrians, broken bones, and numerous other calamities predictable in the age of the horse-drawn carriage.
