Scottish immigrant Walter Lowrie was a county commissioner, justice of the peace, and a Pennsylvania and later a U.S. senator. Built three years after his term in the Senate, this two-story, five-bay house has a four-over-four plan. A kitchen and a scrub room were added at the rear of the house in the 1870s. In 1986, Isabella Shaw left the house to the Butler County Historical Society, which has restored the building as the Lowrie-Shaw House Museum and the society's office. Nearby, at 209 W. Diamond Street, is a log house built c. 1840 on land once owned by Lowrie; it has been restored by local attorneys.