Ohio City is one of the oldest neighborhoods in Cleveland, Ohio. It is located immediately west of the Cuyahoga River. The City of Ohio became an independent municipality on March 3, 1836, splitting from Brooklyn Township. The city grew from a population of 2,400 people in the early 1830s to over 4,000 in 1850. The municipality was annexed by Cleve…Ohio City is one of the oldest neighborhoods in Cleveland, Ohio. It is located immediately west of the Cuyahoga River. The City of Ohio became an independent municipality on March 3, 1836, splitting from Brooklyn Township. The city grew from a population of 2,400 people in the early 1830s to over 4,000 in 1850. The municipality was annexed by Cleveland on June 5, 1854.