Hamilton was founded in 1791 as Fort Hamilton, named after the Secretary of Treasury, Alexander Hamilton. The fort served as a supply station for the troops of Generals Arthur St. Clair and Anthony Wayne.
By 1800, the fort was no longer used for military purposes and Hamilton began transitioning into an active agricultural and regional trading area. The town was mapped, the government was seated, and Hamilton was formally incorporated as a city by the Ohio General Assembly in 1810.
By the mid-1800s, Hamilton had become a significant manufacturing city, producing machines and equipment used to process the region’s farm produce. Completed in 1845, the Hamilton Hydraulic System spurred one of Hamilton’s greatest periods of industrial and population growth from 1840 to 1860. Hamilton Hydraulic was designed to be a system of canals interlocking with natural reservoirs to bring water from the Great Miami River into the city as a power source for future industry. Four miles to the north of Hamilton, a dam was built to funnel water into the Hamilton Hydraulic System along with two reservoirs to store extra water for the new system. The Hamilton Hydraulic System was a high risk/high reward project: while the City of Hamilton did not have many businesses that would need the power when construction began in 1842, if it could be successfully completed, the power generated by the system would bring in more industry. The gamble proved to be a successful one as the project attracted many businesses to the area, including the Beckett Paper Company in the late 1840s. At the time, the City of Hamilton primarily existed on the east bank of the Great Miami River with the community of Rossville on the west bank. Though Rossville constructed its own hydraulic system, it was completed after Hamilton Hydraulic and never was able to gain as much popularity. As a result, in 1854, Rossville decided to merge with the quickly growing City of Hamilton. To this day, the historic neighborhood on the western side of the High–Main Bridge bears the same name it did when it was a separate city.