William O’Brien arrived in Sheridan, Montana, in 1881 and began selling liquor from a small sixteen-by-twenty-foot building in the gold-mining and ranching town. One of the town’s three suppliers of “wet groceries,” he prospered, became a school trustee, one of Sheridan’s original aldermen, and a member of the Montana legislature. In 1889, he bought a large corner lot from the estate of early Sheridan pioneer Hugh Duncan for $160, and five years later built a two-story brick residence there, where he lived with his wife, Mary, and their three daughters. Its size, design, and materials reflected his political and financial success in a town where most homes were wooden. The irregular house showed Italian Renaissance style in its two-story, three-bay façade, restrained porch, wide projecting cornice, hipped roof, segmental brick arches, stone lintels, and walls three bricks deep. William died of Bright’s disease in 1901 at age forty-five, but the home remained in the O’Brien family until 1927.