Mercedes
The 1931 Sanborn map (Sheet 2) depicts a jail in the lower southwest corner of city block 14 (lot 11) next to the fire department at 308 4th Street and city hall at 307 4th. It appears that it faced the alley. It was still there in 1949 (Sheet 2).
Mission
The 1919 Sanborn fire insurance map (Sheet 3) depicts a small one-story wood lockup in the town of Mission, Texas. At the time it was located behind the bank that fronted 417 Lomita Boulevard (city block 174). The side street was Guallacan. This was the only Sanborn map available during this study.
Mission 1919
San Juan
The Sanborn map dated 1925 (Sheet 2) depicts a concrete city jail in the lower half of city block 38 facing an alley between it and city block 39. It was in city lot 23. Map says built 1922. It was still there in 1938 (Sheet 4). Does not appear on Google Earth.