Hartford City is a city in the U.S. state of Indiana, and the county seat of Blackford County. Located in the northeast central portion of the state, the small farming community experienced a 15-year “boom” beginning in the late 1880s. The Indiana Gas Boom was caused by the discovery of natural gas in the area, and it caused the community to transition from an agricultural economy to one that also included manufacturing. The boom brought residents, retail establishments, and craftspeople. The increased population meant construction of new roads, schools, and churches. After the boom came a long period of growth and stability. Agriculture remained as the fundamental industry.From the 1920s through the 1970s, Hartford City continued to thrive. Agricultural automation and consolidation of small farms into industrial-size farms started a decline in the population as the small farmer became unable to compete and fewer people were required as laborers.