Final answer:
The provided reference does not mention the year Oklahoma TSA co-hosted the National Conference with Texas TSA; it focuses instead on transgender history and organizations.
Step-by-step explanation:
The year that Oklahoma TSA co-hosted the National Conference with Texas TSA is not provided in the reference information given. However, the information provided showcases significant events regarding transgender history and organizations in the United States during the late twentieth century.
It talks about the emergence of transgender organizations like FTM International and International Foundation for Gender Education as well as landmark events like the Southern Comfort transgender conference and the work of activists like Phillis Frye. The given reference does not specifically address the Technology Student Association (TSA) or their national conference events.