Tradition has it the adventurer Matthew F. Rainey became the first resident of El Dorado by accident. Rainey's wagon broke down there in 1843, and being unable to get replacement parts, he held a sale of his possessions. The sale went so well that he bought more goods and opened a store.

El Dorado is Spanish for "the gilded one." It is not known if Rainey was responsible for naming his new home in recognition of his good fortune. The name was in use, however, the following year when Union County officials, seeking to move their county seat from the Ouachita River bluff (now Champagnolle), accepted Rainey's donation of 160 acres for the new townsite. In 1851, the town, then one square mile in area, was incorporated. Cotton growers came up the Ouachita River by steamboat and cleared the land for plantations.

William Paca Chew and his family moved to El Dorado between 1850 and 1857. Since he was a "lumberman" he probably had a hand in clearing the land for the cotton plantations. His grandson, our grandfather Robert Hamilton Chew, would farm cotton in Arkansas and Oklahoma in later years.

By 1890, there were 455 people in El Dorado. The 30-year period following this saw El Dorado's population grow to about 4,000 people and the town developed into the agricultural and timber center of South Arkansas. On January 10, 1921, the Bussey Oil Well blew and "black gold" began to flow. In a matter of weeks, El Dorado's population grew to over 20,000 people. El Dorado was transformed from a settled, sleepy little community to a boomtown. By the end of October, about 460 producing wells had been drilled and 10 million barrels of oil had been taken from the area.

Martha Chew remained in El Dorado while her son Robert Hamilton moved on to Arkansas.