The workhorses of the Chicago harbor were the tugboats. During the 1870s, a tow from outside the breakwater to a berth in the river could cost as much as $25. During slack periods in the economy, which were frequent in the 1890s, tugboats desperate to recruit work would sometimes steam out as far as Milwaukee to find schooners in need of a harbor tow.
Among the most important tugs on the Chicago River were those operated by the fire department. Due to the disgusting array of pollution in the river, a mixture of industrial waste and run-off from streets reeking of horse droppings, the surface became combustible every summer.
Long after most other shipping abandoned the Chicago River harbor, tugboats continued to utilize the waterway.