For much of its history, Kaufman County depended upon agriculture and ranching for its economic growth. The wide variety of soils permitted many different crops for many years. Today, there is perhaps more emphais upon ranching and light industry as the county grows due to its proximity to the Dallas metroplex.

In October 1903, the success of techniques proposed by the U.S. Department of Agriculture to increase productivity was proven at the Porter Farm near Terrell. A network of farm demonstration agents was quickly built which brought these techniques to the farmers of the nations. Such was the importance of the methods deomonstration through the "Terrell Plan." The U.S. Department of the Interior erected an official plaque at the farm commemorating its establishment. At the time, the only similar marker in Texas was at the San Jacinto battleground. A centennial celebration for the Porter Farm will place in Kaufman County in October of 2003.