In total, he served as Detroit"s mayor for five other terms. He also was a brigadier general in the United States Army during the Black Hawk War. Born in Detroit, he was baptized as John Williams (he later adopted the ‘R’ in his name to distinguish himself from another John Williams who was living in Detroit at the time).
One of them, Thomas Williams, would later be killed in action as a Union general during the American Civil War.
Williams served in the Territorial Militia from 1796 to 1799 at Fort Marsac in Tennessee. During the War of 1812, Williams again served in the militia, this time as the captain of an artillery company.
After the end of the war, Williams was appointed Associate Justice of the County Court for Michigan in 1815. He went on to serve as a County Commissioner and Adjutant General of the Territory, and at his death was the senior Major General of the state militia.
In 1824, Williams wrote the City Charter and served as the first official mayor of the City of Detroit.
He was also elected and served as the fourth and thirteenth mayor in 1830 and 1844–1846, respectively. Besides serving as mayor, Williams was a landowner, merchant, and bank president during his lifetime. He served as one of the first trustees of the University of Michigan, was president of the Detroit Board of Education, and was a delegate to the first Michigan Constitutional Convention.
Williams died at the age of seventy-two on October 20, 1854.
He is interred at Elmwood Cemetery in Detroit. Today, a street in metropolitan Detroit bears his name.
"John R" Street was named while Williams was still living, atypical to the way most roads obtain their name (which is usually posthumously). In fact, Williams gave the road its name himself.