What was the mission that served as a halfway mark between Mexico and the eastern settlements? I have no clue and cannot find it in my history book...

After the eastern settlement and related missions were closed, Mission San Antonio de Valero became an important Mexican Fortress, until Col Bowie took it. It is famous under another name.

What is the other name?

http://www.nps.gov/nr/twhp/wwwlps/lessons/2sanantonio/2sanantonio.htm

San Antonio de los Tejas

To identify the mission that served as a halfway point between Mexico and the eastern settlements, we can follow a step-by-step approach to find the answer.

1. Start by understanding the geography: Based on your question, we know that the mission is positioned between Mexico and the eastern settlements. This suggests that we are looking for a mission located somewhere in the middle of these two regions.

2. Next, consider the historical context: Knowing the historical context will help us determine the time period and context in which the mission existed. This will assist in narrowing down the possibilities.

3. Conduct research: Once we have the geographical and historical context, we can search for information using available resources. These resources include history books, academic journals, articles, and trusted online sources.

4. Utilize search engines: Entering a combination of search terms, such as "mission between Mexico and eastern settlements" or "missions in [specific historical period]," into a search engine can yield relevant results.

5. Verify sources: Once you find potential missions fitting the requirements, check multiple sources to validate the information and ensure accuracy.

Since you mentioned being unable to find the specific mission in your history book, it might be helpful to explore alternative resources beyond your book. Online databases, historical websites, or consulting with a history teacher or librarian could provide additional insight and help you discover the answer you're seeking.

Good luck with your research!