I know, I know... This isn't Chihuahua, it's Monclova. Chihuahua is southwest of Fort Leaton.
It is about here that missionaries and soldiers from the Texas outposts would intersect the road between Mexico City and its far flung North American capital at Santa Fe. Except for the infrequent safety of passage of their roads to Taos and El Paso, this was the North American border for the rulers of Mexico.
During the three centuries that Spain, and at the end, Mexico, ruled this part of America,
for the most part, this was the northwest boundary