In 1885 David R. Francis became the thirtieth Mayor of St. Louis.
The Democratic City convention nominated him for office of Mayor in 1885 and he was declared elected.
Mayor Francis reduced the rate of interest on City indebtedness from six per cent to four per cent. Reforms were inaugurated in the conduct of business by the departments of the city government. He was instrumental in getting the gas rates to the consumer, reduced from $2.50 to $1.25 per thousand feet. He directed the start of an expansion of the Waterworks with a new pumping station and reservoirs at Chain of Rocks in north St. Louis. The reconstruction of city streets to make them more durable was pushed forward. The city's population increased from 350,518 in 1880 to 451,770 in 1890.
Mayor Francis helped St. Louis to become famous as a Convention City. He vetoed what was known as the 'Electric Elevated Railway Bill', because he felt it did not adequately compensate the City for a valuable franchise. Francis, and other leading businessmen, in 1886, organized the Merchants' Bridge Company to build the railroad bridge just south of the Bissell's Point Waterworks station. In 1887 he approved the start of Milk Inspection Service in the City.