Louisiana became the 18th state in 1812. The Louisiana quarter features the state bird (brown pelican), a musical symbol for New Orleans Jazz, and an outline of the original Louisiana purchase (public domain image on Wikipedia).
The Pelican State
The nickname for Louisiana is The Pelican State. The brown pelican is the state bird and appears on Louisiana's state flag, great seal, the official state painting (along with many other symbols and icons of Louisiana), and is one of three Louisiana symbols displayed on the U.S. mint's bicentennial Louisiana quarter.