Although the provisions of the Texas Annexation document allowing for the creation of four additional states are popularly regarded as a unique curiosity today, they were largely superfluous. Article IV, Section 3 of the U.S. Constitution already specifically provided for the formation of new states through the junction or division of existing states
That would be one heck of a way to Gerrymander the Senate.
no subject
http://www.snopes.com/history/american/texas.asp
Also from that link:
That would be one heck of a way to Gerrymander the Senate.