Jim --
There are a couple of minor corrections to the information you posted about this single card. First, the site of the surrender agreement was New Orleans, not Mississippi. That means that the Confederate officer named, General E. Kirby Smith, agreed to surrender soldiers under his command. It should not be understood to mean that all of Kirby Smith's soldiers came to New Orleans -- in fact, none of them did. The roster was compiled at the camp site of Benevides' Cavalry Regiment, which was not posted.
Second, Laredo is cited as the residence of H. B. Bush, not his home base.