Recent years have seen a wave of projects involving flags. Some are from Southern states like Georgia and Mississippi that are just now eliminating Confederate imagery from their flags, imagery that dated from the 1960s, not the 1860s, by the way.
Southern states tended to have distinctive flags, while states tied to the Union cause tended to feature something that basically looked like a regimental banner of dark blue with some sort of seal in the middle. The message was not subtle. Southern states emphasized unique state identities, while northern states tended to favor being part of the larger union — Ohio and Virginia being exceptions to that rule. Kansas actually added the word Kansas to its state flag in 1961 to keep it from being mistaken for two dozen other flags.
Recently, there have been moves among these northern states to replace the regimental banner format with something more bespoke. For example, Utah and Minnesota have recently redesigned their state flags. There are other states that have had similar campaigns, but not as successful. It is part of a larger trend to reconsider flags, from states to cities, to adopt or create distinct flags. We live in a time where proclaiming identity is a big deal, and one way to do that is to hoist something up the flagpole and see who salutes.