The Harvey-Niemeyer House, in Florence, Arizona, is a one-story house built around 1874. It was listed on the National Register of Historic Places in 1986, as a result of a study of historic resources in the Florence area.It was built first as a T-shaped adobe house, which was probably flat-roofed, with an attached front porch and a rear frame addition, around 1874. It was renovated in 1892 with addition of a hipped roof and a veneer of fired brick on all but the rear facade. It was expanded also with a row of rooms across its rear in 1936.It was deemed significant as "an outstanding example of a local architectural type known as 'Early Transitional.' Early Transitional buildings manifest characteristics of both Sonoran and American Victorian styles. The building is also associated with two locally significant individuals: Dr. William Harvey, M.D., and Charles H. Niemeyer." It was judged to be comparable to the best examples of Early Transitional style in the National Register-listed Florence Townsite Historic District.It is located outside that district at 250 S. Main St., but when it was listed its address was 1618 Main St.It is a one-story house built of adobe around 1874. It was remodeled in 1892 and expanded in 1936. It is about 42 by 45 feet (13 m × 14 m) in plan.It was home of physician William Harvey, who became known as an "Angel of Mercy" during a smallpox epidemic. Harvey also came to address the aftermath of the 1888 Gabriel-Phy shootout. Charles Niemeyer, a later homeowner, served as a postmaster and, for 25 years, as Clerk of the Pinal County Board of Supervisors.