On May 20, 1862, W. G. M. Samuel at the Texas Arsenal in San Antonio wrote to Capt. George R. Wilson in Houston, telling him that he had bought 5730 pounds of fine rifle powder and 653 pounds of cannon powder and a small lot of lead. "The powder was made at San Luis Potosi, Mexico, and is a first rate article." The letter is in Fold3 (formerly Footnote.com) at http://www.fold3.com/image/#74311787. It is from W. G. M. Samuel's military records, Confederate officers.

I've done quite a bit of annotating through the Texas officers files. You might find other good sources by searching for "san antonio texas" and "powder" or "gunpowder" or perhaps Laredo or Brownsville or Mexico. One of the problems is that the place and the topic must appear on the same page for them to pull up together, and sometimes that doesn't happen in longer correspondence. If you have access to this database, just play around a little with the search terms.

Vicki Betts