I want to thank John Walker for letting me link to a couple of Brazosport Archeological Society monographs he has posted to his Web site, "Life On The Brazos River."
This first paper is on the Durazno Plantation, which was located on land Stephen F. Austin owned south of present-day Angleton. Click here to view the paper. Austin's nephew, William Joel Bryan, inherited the land through his mother (Austin's sister Emily) and eventually established a plantation there with a sugar mill. The monograph goes into great detail about this site and includes numerous photos.
The next paper is also from the Brazosport Archeological Society. Its topic is the Osceola Plantation up-river of Columbia. This property is connected to the Austin family through James Austin, Stephen's brother. Click here to view the paper. The Archeological Society has done extensive research on the plantation - note the modern photos of its ruins included the paper.