Many of the states that formed the Confederacy had only been a part of the United States of America for less than fifty years! Heck.....even I can remember fifty years ago, and if fifty years ago, my family, friends, and neighbours had voted to "join" the USA, I sure we would feel no compunction at deciding to leave and form a more perfect union with states that respected the constitution.
Statehood:
Louisiana - 1812
Mississippi - 1817
Alabama - 1819
Arkansas - 1836
Florida - 1845
Texas - 1845