Complex sentence: In the case of Mississippi, Florida, and Alabama, these new flags were adopted around the same time that new Jim Crow segregation laws were being enacted; these laws disenfranchised African American voters for the next several decades.
Split into simpler sentences: In the case of Mississippi, Florida, and Alabama, these new flags were adopted around the same time that new Jim Crow segregation laws were being enacted. These laws disenfranchised African American voters for the next several decades.