When viewed from the twenty-first century, the effects that mechanization has had on farm productivity and on American society are profound. With mechanization came both specialization and standardization. Farmers needed new types of crops and new methods of farming to maximize the profit from investments in expensive new equipment. They also needed to produce more to make the same profits as before, leading to larger and larger farms and, simultaneously, the decline of the traditional small family farm. In 1920, an estimated 6.45 million farms were operating in the United States. By 2004, the number of American farms had declined to only about 2.1 million.