Defiance is the county seat of Defiance County, Ohio. The city was named for Fort Defiance, which once stood in the confines of the city. In August 1794, General Anthony Wayne ordered the construction of Fort Defiance at the confluence of the Auglaize and Maumee Rivers. Wayne built the fort during his campaign against the Native Americans of Ohio to provide his men with protection and a staging ground for their operations. The fort was a rough square with a blockhouse located on each corner. In addition to the stockade, a wall of earth eight feet thick and a ditch eight feet deep and fifteen feet wide protected the fortifications. Lieutenant John Boyer, an officer in Wayne's army, claimed that the fort could protect the American soldiers from "the English, the Indians, and all the devils in hell."
Following the Battle of Fallen Timbers, Wayne utilized Fort Defiance as his base of operations. He ordered the destruction of all Native American villages and crops within a fifty mile radius of the fort. When Native Americans and the United States signed the Treaty of Greeneville in 1795, the natives permitted the Americans to maintain a trading post and fort at Fort Defiance, although the whites had ceded the right to settle this portion of Ohio. Until the War of 1812, Fort Defiance served as one of the western-most outposts in Ohio, guarding citizens from native attacks. William Henry Harrison utilized the fort in his attacks against Native Americans in the early 1810s as well as a staging area for attacks against the British in the War of 1812. Modern-day Defiance, Ohio, was founded at the fort's location in 1822. Local Native American tribes had signed away their rights to the surrounding land in 1817.
Defiance grew slowly, having approximately seven hundred residents in 1846. That same year, the town consisted of two churches and five retail stores. Over the next thirty-four years, Defiance's population increased dramatically to 5,907 residents in 1880. This growth resulted from two railroads passing through the town, as well as the need for businesses to meet the needs of farmers living in the surrounding countryside. In 1886, four newspaper offices, thirteen churches, and two banks existed in the community. The largest single employer in Defiance was the Turnbull Wagon Company, which employed 190 workers. Numerous other businesses produced wagons, carriages, and agricultural implements for local farmers.
During the twentieth century, Defiance continued to grow. In 2000, 16,465 residents lived in the town. Many of the local businesses continue to serve farmers living in the surrounding countryside. Founded in 1850, Defiance College also is a major institution in the community.