Toledo has been a part of Ohio since its statehood in 1803. However, early maps of Michigan included the "Toledo Strip", an area of land stretching from Indiana to Lake Erie, containing the city of Toledo, as well as the Maumee River Bay. When Michigan sought statehood in the early 1830s, they included a small town called Toledo, MI in their survey of the land. Neither state ceded the land to the other.
In 1835, Ohio, having enough of this, raised a militia and sent it to the border. Laws were made against citizens submitting to the Michigan's laws. Michigan reacted similarly, also sending troops.
Shots were fired, but there were no actual casualties during the "war". However, when a Michigan deputy attempted to arrest an Ohioan, he was stabbed, and this is considered the only injury of the conflict.
In 1836, Congress pressured Michigan to give the land up. Today, Toledo and the Toledo Strip are both part of Ohio.