Horses are built for power. Their muscular bodies are heavier in front than in back, making them well balanced to pull heavy loads. Yet they can also be agile and quick--fit to carry out difficult tasks at top speed.

For more than 1,000 years, people have called on the power of horses to achieve their own ends. Horses have cleared forests, plowed land, herded cattle, and driven machines. Over time, horses bred for different jobs have become heavier, stronger, or more flexible. As people have shaped horses, horses and humans working together have shaped the world in remarkable ways.