Indiana Gas Boom. Hartford City's population tripled in the next decade, as manufacturers were lured to the region to take advantage of low costs for land and the natural gas. Hartford City benefited from railroad service from two railroads in addition to a natural gas supply that was thought to be unlimited. Manufacturers such as Hartford City Glass Company, Sneath Glass Company, Hartford City Paper, Utility Paper, and Willman Lumber all located or began in Hartford City during the 1890s. Although the supply of natural gas was soon exhausted, many of these businesses continued to operate into the 1950s and beyond. Hartford City leaders attracted businesses such as Overhead Door (1923) and 3M (1955) to replace the glass factories as major employers in the city. Geography Hartford City is located at (40.4525, -85.3693). The area sits on top of former natural gas fields. The area also has limestone formed from silt and mud deposits of an ancient sea. The land is flat from the effect of a prehistoric glacier, and the soil is excellent for farming. According to the 2010 census, Hartford City has a total area of , of which (or 99.46%) is land and (or 0.54%) is water. Major highways Indiana State Road 3 Indiana State Road 26 Interstate 69 (less than west of city) Adjacent cities Upland − about 8 highway miles west Montpelier − about 12 highway miles northeast Dunkirk − about 14 highway miles southeast Muncie − about 19 highway miles south Marion − about 23 highway miles northwest Climate Hartford City has a typical Midwestern humid continental seasonal climate. There are four distinct seasons, with winters being cold with moderate snowfall, while summers can be warm and humid. The highest average temperature is in July at , while the lowest average temperature is in January at . However, summer temperatures can top , and winter temperatures can drop below . Average monthly precipitation ranges from about , with the heaviest occurring during June, July, and August. The highest recorded temperature was on June 25, 1988, and the lowest recorded temperature was on January 19, 1994. Demographics 2010 census As of the 2010 United States Census, there were 6,220 people, 2,666 households, and 1,691 families in the city. The population density was . There were 3,158 housing units at an average density of . The racial makeup of the city was 97.3% White, 0.3% African