William Hyser (1826-1909), who was a pioneer surgeon and Civil War captain, came to Plainfield Township in 1850, when it was a lumber center. In 1852 he built this Greek Revival house as a home and an office for his medical and civic duties.

He was at various times township clerk, school inspector and supervisor, and justice of the peace. The house has also served as a stagecoach station and a post office.

In 1976 the home was moved to its present site. The only remaining structure from the original Plainfield village, it is now restored as a museum.

Plainfield was first settled in 1838. Its post office, known as the Austerlitz office because there was a Plainfield post office elsewhere, was established in 1843. It was later housed in this structure for a short time. In the days before envelopes, letters were folded and closed by sealing wax and other means. The Austerlitz office operated until 1913 when it was consolidated into the one at Belmont.