Until the end of the 18th century, agriculture was the predominant industry in every country. The advent of the steam engine and Eli Whitney's concept of standardized parts paved the way for the Industrial Revolution with its large manufacturing facilities powered by steam or water. A number of countries (the United States included) evolved from an agricultural economy to an industrial economy. But for a time, manufacturing was more of an art than a science. This changed with the introduction of Frederick W. Taylor's systematic approach to scientific management at the beginning of the twentieth century. The introduction of Taylor's method of scientific management and Henry Ford's moving assembly line brought the world into an age where management was predominantly centered around the production of goods.