Doctor John Henry Holliday
Denison was founded in 1872 in conjunction with the Missouri–Kansas–Texas Railroad (MKT) or "Katy" depot. It was named after the wealthy Katy vice president George Denison. Because the town was established at the intersection of the MKT and the Red River (both important conduits of transportation in the industrial era), it came to be an important commercial center in the 19th century American West. In 1875, Doc Holliday, the notorious gunfighter, had his dental offices on Main Street in Denison. When approached about a killing in Dallas, Holliday suddenly relocated to Colorado.
During the phylloxera epidemic of the mid-19th century, which destroyed the vast majority of wine grapes in Europe, Denison horticulturalist T.V. Munson pioneered methods in creating phylloxera resistant vines, and earned induction into the French Legion of Honor, as well as sister city status for Denison with Cognac, France.
In 1901 the first electric "Interurban" railway in Texas, the Denison and Sherman Railway, was completed between Denison and Sherman, Texas.
In 1915, the Kentucky-based evangelist Mordecai Ham held a revival meeting in Denison, which resulted in 1,100 professions of faith in Jesus Christ.
Denison played host to 20th century notables such as the Marx Brothers and President Dwight D. Eisenhower, who was born on October 14, 1890, in Denison.