It's fairly well-known that Michigan and Ohio became embroiled in the Toledo War over the "Toledo Strip", and that in return for ceding territory a few miles north to Ohio, Michigan received what is now the Upper Peninsula. That explains the current Michigan-Ohio border.
What I have never been able to find out though it why Indiana's border with Michigan runs a few miles off north from Ohio's boundary (even after Ohio getting the Toledo Strip). I do know that over the years there's been debate as to where Indiana's border with Michigan even actually is, but it seems odd that Indiana got its border something like 4 or 5 extra miles north of Ohio's, resulting in the weird angle around Clear Lake in Indiana, east of Fremont.
So why are Indiana and Ohio's borders different? Why didn't Indiana just end up with a border that was a continuation of Ohio's? Is there an actual reason?
EDIT: Typos fixed.
As Congress began to divide the Northwest Territory into states, the intention was to set borders at the southern tip of Lake Michigan. That's neat on a map, but ignores the reality of 19th century transportation, which was dominated by lake and river navigation.
As you've noted, the northern border of Ohio was adjusted so that the mouth of a key river, the Maumee, would be within the new state. That caused friction with Michigan, resulting in the Toledo War.
A few years later, Indiana's northern border was also adjusted 10 miles northward to give it access to Lake Michigan, which since the opening of the Erie Canal in 1825 had become economically very important.
In a similar vein, the boundary of Illinois was pushed northward nearly 60 miles so that the Chicago River, one end of a planned canal connecting the Great Lakes and the Mississippi, would be within a single state.
An entertaining source for such border trivia is Mark Stein's book How the States Got Their Shapes.