Designed by architect Alfred Giles and built by contractor John H. Kampmann, this estate was completed in 1880 for one of the founders of the Groos National Bank, Carl W. A. Groos. Emigrating from Germany in 1848, Groos and his brothers established a successful freighting firm in New Braunfels, Texas, before moving to San Antonio in 1872. The property occupies 0.7 acres along the bank of the San Antonio River, its two-story, cream-colored limestone mansion designed in the Victorian Gothic Revival style. The home’s covered porches feature distinctive blue-green columns, balustrades, and gingerbread with intricate iron detailing and Corinthian capitals.
The perimeter of the property is enclosed by a four-foot-high limestone wall topped with highly decorative, ornamental iron fencing. It is entered from King William Street through an iron gate flanked by twin limestone piers. A central, stone-paved path leads through a generous front lawn designed with Victorian principles of simplicity, structure, and order. Planted with live oaks and Texas sabal palms, the lawn is divided into four quadrants by the main walkway and another that crosses perpendicular to it, leading to two small cul-de-sacs at either end. The southern cul-de-sac features a large crape myrtle while the northern hosts a circular pool, at the center of which is a sculptural fountain surmounted by a small cherub surrounded by ferns. Groos’ descendants occupied the property until 1948, after which it passed into other private ownership. It was acquired by the San Antonio Area Council of Girl Scouts, Inc., in 1957. The Carl Wilhelm August Groos House is a contributing feature of the King William Historic District, listed in the National Register of Historic Places in 1972.