Complex sentence: A map discovered by Zorro delineates two states (Arizona and New Mexico) that did not achieve statehood until 1912; several other states depicted on the map entered into the Union long after California.
Split into simpler sentences: A map discovered by Zorro delineates two states (Arizona and New Mexico) that did not achieve statehood until 1912. Finally, several other states depicted on the map entered into the Union long after California.