At the dawn of the 20th century, America is transforming from a primitive agrarian society to a modern Mecca of technology, mass production and automation. Factories are stocked full of machines that require maintenance from new tools. With a growing need for speed and efficiency, a few visionary companies–Black and Decker, Milwaukee, DeWalt–create the power tools that revolutionize how America is built, and how many Americans spend their weekends now.