Rapid urbanization which was largely a product of the intercity steam railroad, led to a huge increase in the use of animal power for travel within cities. Yet, urban steam locomotives remained anathema, despite the widespread use of stationary steam engines within cities.  

Beginning in the early 1860s, inventors developed steam streetcar engines that produced little smoke, steam, or noise. Although these engines found a significant niche on suburban streets in both Europe and the United States, they rarely penetrated the urban core. Meeting the regulations raised costs so much that steamcars lost any economic advantage they may have had over horse-cars.

The electric streetcar, in contrast, would manage to avoid such strict environmental regulation—but not without a struggle.

• Before electric streetcars, cities were involved in another fight to regulate electrical technologies in the streets: fight against overhead telegraph, telephone and electric-lighting wires. By the early 1880s, a haphazard web of overhead wires cluttered the downtown streets of every large American city. Overloaded poles sometimes collapsed under the weight of hundreds of wires.