George,

Union soldiers captured William on October 21, 1863 at Bayou Teche was the 19th Army Corps. Was the 19th Army Corps the same one you mentioned on this link?

http://history-sites.com/cgi-bin/bbs62x/lacwmb/webbbs_config.pl?md=read;id=11361

They were part of the Western Louisiana ("Teche") Campaign October 3-17, 1863.

Scott