Final answer:
The number of Texans in jail has only moved in one direction since more prisons were built up: True.
Step-by-step explanation:
The statement that the number of Texans in jail has only moved in one direction since more prisons were built up is True. According to the provided information, federal statistics show that the prison population in the United States has significantly expanded over the years. From 1970 to 2010, the number of inmates increased from 200,000 to 2.2 million. This indicates that the number of incarcerated individuals has consistently risen with the construction of more prisons.