How Rivers Quietly Change State Borders (with music) (duplicated)

Did you know a city can legally change states without moving a single inch? For centuries,

state borders along the Mississippi River were defined by the river itself. Legally,

that border follows the river’s deepest channel, called the thalweg. But the Mississippi

doesn’t stay still. It naturally bends, shifts, and migrates over time.

When the river slowly moves, the border moves with it — this is called accretion.

But when floods cause the river to suddenly jump course, the border freezes

in place. Early lawmakers never imagined the Mississippi’s constant movement,

but their legal definitions locked modern borders to a river that refuses to stay put.