The three theories are warfare between city-state, overpopulation, and drought.
The convention adopted an "Ordinance of Secession" by a vote of 166 to 8, which was ratified by a popular referendum on February 23. ... — Texas Secession Convention, A Declaration of the Causes which Impel the State of Texas to Secede from the Federal Union,
they connected becasue they agreed with each other.
