William Dunbar, plantation owner, scientist, and explorer, son of Sir Archibald and Anne (Bayne) Dunbar, was born in Morayshire, Scotland, about 1750. In 1763 he attended King's College, Aberdeen, and graduated from there in 1767. Deciding to seek health and fortune in America, he arrived in Philadelphia in April 1771. In 1773 he formed a partnership with John Ross, a Scotch merchant in Philadelphia, and they established a plantation in West Florida. Dunbar opened another plantation called "The Forest" near Natchez, Mississippi, in 1792. Applying his knowledge of chemistry and mechanics to planting, he made a number of inventions and became sufficiently prosperous to retire and devote his time to scientific investigation. Dunbar invented a screw press and with its use introduced square cotton bales as a means of packing cotton. He was the first to suggest the manufacture of cottonseed oil. He was surveyor general in the Natchez area in 1798 and made the first meteorological observations in the Mississippi Valley in 1799. In 1804 he was appointed by President Thomas Jefferson to head an expedition with Dr. George Hunter. They were to explore the Ouachita River region and travel all the way to the source of the Red River. The Hunter-Dunbar expedition set out on October 16, 1804, traveling up the Ouachita River and on to the area of Hot Springs, Arkansas. Dunbar became the first man to give a scientific report of the hot springs, and his journal of the exploration was later published in Documents Relating to the Purchase and Exploration of Louisiana (1904). He made scientific reports on the Indian sign language, animal and plant life, fossils, and astronomical phenomena in the area. Dunbar never explored the Red River region and was never in Texan territory, however. He was later chief justice of the Mississippi Court of Quarter Sessions and a member of the Mississippi Territorial Legislature. He was a member of the American Philosophical Society. At some point in his life he married Dinah Clark. They had several children, although specific details are unknown. Dunbar died on October 16, 1810, in Mississippi.