Adopted in 1902. Ohio was once part of the Northwest Territory created by the United States in 1787, after Britian ceded claims to its western territories at the end of the American Revolution. Ohio became the 17th state in 1803. The Ohio burgee, as the swallow-tailed design is properly called, was designed in 1901 by John Eisenmann, architect and designer for Ohio Building at the Pan-American Exposition being held in Buffalo, New York. The Ohio flag has three red and two white horizontal stripes.