I've got one that I'm looking at in Galveston, but it's pricier than the one in Matagorda and less historic.
(The interior is gorgeous, as you'd expect.)
The options are really limited because I have "must predate Civil War" on the list of criteria.
https://www.realtor.com/realestateandhomes-detail/2314-Avenue-M_Galveston_TX_77550_M72922-87156