All flags from my project without a formal write-up yet, the Bravura timeline:
(Note the central artwork is not mine and is only modified from publicly available sources. The pelican's blood drops were modified.)
Louisiana's flag is a blue field defaced with a pelican feeding her young, encircled with the words 'Union', 'Justice', and 'Confidence'. Louisiana's classic "pelican in piety" is actually feeding her chicks blood from her own breast, apparently according to the mythos unable to otherwise source their food.
When the nascent Republic of Texas was admitted into the United States, Texian and Congressional negotiators significantly cut down its size and subsequently split it in two. The eastern portion had to find a new name and flag and so became the State of Jacinto, named for the decisive victory at the battle of San Jacinto.
The flag retains the symbolism of the lone star, as in the Texas flag, but is more directly reminiscent of the classic Bonnie Blue flag with a single gold star on a deep blue field. No less the egoists as their former Texas selves, the early Jacinto legislature took special care to make their lone star a little bigger than that of their neighboring state.
The flag of Mississippi harks back to the first European explorers of the river and suggests the French tricolore, but with an expanisve red field encompassing two-thirds of the fly. The central white band is bendy (yes, that is the technical term), symbolizing the great river itself. Five white stars in the red represent the state's history with the French, Spanish, British, Confederates, and Americans.
Sequoia, the 46th state. Count 'em up if you like, but in this state, they'd SOONER tell you outright. And so here's the flag.
A blue field defaced with a white star surrounded by forty-five others in the shape of a circle, the central star is fibriated in red and itself defaced, in red, with the numeral "46".
The flag of Missouri borrows from the official state heraldic elements - the canton depicts a gold crescent on a blue field, the lower hoist is a gold bear on red (in the state Coat of Arms, the bear is brown), and the fly is plain white (here again, the flag differs from the CoA, which here includes the entire Seal of the United States - a little much for a flag). Everything is fimbriated in gold despite breaking heraldic rules because Americans don't care about heraldic rules.
The square shape of the flag is shared with only one other US state: Alabama.
((The bear is borrowed from publicly available sources and is Russian in origin. I also think it is technically supposed to be a polar bear.))