Born in Pennsylvania on January 13, 1775, he married an Irish woman named Susan in 1798, and the couple would eventually have nine children. Looking for farmland, he and his wife moved to Tennessee and, in 1802, to St. Clair County, Illinois.
Making a living logging and fur trapping, he met Forest Hancock, who had settled in Missouri with Daniel Boone. From Boone, Hancock learned about the Lewis and Clark Expedition. Dickson and Hancock soon decided to follow the expedition, starting in August 1804.
The following spring, they joined Charles Courtin’s trapping group for protection and spent the winter of 1805 at a camp of Teton Sioux. Before they left in the spring of 1806, they were robbed of their pelts, and Dickson was wounded in a fight. Continuing, Dickson and Hancock met the returning Lewis and Clark expedition in the summer of 1806. The expedition helped the pair re-supply, and John Colter accompanied them upriver to the Yellowstone River. Dickson was among the fourth party of white men known to have reached the mouth of the Yellowstone River.
For whatever reasons, Dickson wintered alone in the Yellowstone country, some say over a dispute with Hancock and Colter. During the winter, he suffered a siege of snow blindness and was sure he would die alone in the wilderness, but after praying for help, he made a poultice from the bark of a tree which restored his sight.
Converted to Christianity after that, he determined to return to Illinois and settle down. He took his pelts back to St. Louis, sold them for a profit, and was back in Illinois by August 1807. Afterward, he farmed in the summer, trapped locally in the winter, and became a staunch supporter of Methodism.
In 1818, he moved his family into Sangamon County in central Illinois and built the first “white man’s” cabin in the area. Over the next several years, he bought some 240 acres of land. He died in Franklin, Illinois, in 1844.