Broadway & Union Square, New York /

Streetcars or trolley or tram were once the chief mode of public transit in hundreds of cities and towns. From the 1820s to the 1880s urban transit in many cities began with horse-drawn omnibus lines. Horsecar lines ran wagons along rails set in a city so the rolling resistance of the vehicle is lowered and the speed increased. North America's first streetcar lines opened in 1832 from downtown New York City to Harlem by the New York and Harlem Railroad, in 1834 in New Orleans, and in 1849 in Toronto along the Williams Omnibus Bus Line. In many cities, mule-drawn or horse-drawn streetcars drawn by a single animal were known as "bobtail streetcars". By the mid-1880s, there were 415 street railway companies in the U.S. operating over 6,000 miles (9,700 km) of track and carrying 188 million passengers per year using animal-drawn cars. In the 1860s, streetcar operators started switched from animals to steam engines or cable power. San Francisco's cable car system continues to operate to this day. After 1893 electricity-powered cars dominate. Los Angeles built the largest electric tramway system in the world, which grew to over 1600 km of track. The rapid growth of streetcar systems led to the widespread ability of people to live outside of a city and commute into it for work on a daily basis. By 1895 almost 900 electric street railways and nearly 11,000 miles (18,000 km) of track had been built in the United States. The Great Depression of the 1930s led to the closure of many streetcar lines in North America. By the 1960s most North American streetcar lines were closed.