The red area highlights the Toledo Strip.
That's a mighty fine deal, eh?
It was just a mere 180 years ago on this day
that some Michigan delegates met in Ann Arbor to duel it out over a single strip of land that at the time was called the "Toledo Strip."
Ohio was already a state at this point and Michigan so badly wanted to become one. Michigan wanted the Toledo Strip because of it's proximity to Lake Erie — it was super resourceful and would be good for the economy.
Some poor map drawing put the Strip into question of which territory should it belong to. When Michigan tried to become a state in 1833, Ohio said that they had to clearly define the border. This disagreement led to militias from both states to occupy the space. Enter, the Toledo War (that no one died in).
Fast forward to 1836 and Congress offers Michigan a compromise. Ohio gets the Toledo strip and Michigan gets the Western part of the Upper Peninsula (they already had the Eastern portion). At the time it seemed like an awful trade because the U.P. was just a vast wilderness of nothing. Turns out, mass mineral deposits were found in the U.P., there was a ton of wood to be used during the logging boom, and it became a place of travel due to the views and sights. It 'twas a happy ending for all. Yay!
See also: 18 historic (and not so historic) maps of Michigan