As the town grew and traffic on the road increased after the Civil War, the Vances added a second story to the store building in 1874 to provide rooms for overnight guests.

In 1854, the Vances sold the riverfront portion of his property to George L. Haass and Laurent Quintle, who built a dam on the river and constructed a water-powered grist mill to process grain and gin cotton for local farmers.

When Joseph Jr. and Julia Courand took over from his parents, the mill was processing lumber, cotton, wheat, and over a million bushels of corn per year starting in the 1880s.

Jordan T. Lawler bought the Courand property in 1925 and converted the mill to a hydroelectric plant to provide Castroville with electricity for the first time.

The historic hotel re-opened as the Landmark Inn on July 4, 1942, primarily serving military personnel between the air bases in San Antonio and Hondo.

While the rooms have furnishings that reinforce the historical interpretation of the site, they also have modern conveniences, such as electricity, indoor plumbing, and climate control systems.