Irish immigrant who arrived in America at the close of the Revolution. Settled in York, Pennsylvania; taught school, studied surveying, moved west and eventually laid out the town of Meadville. Appointed state District Surveyor and was elected to the state Senate in 1800, defeating General Meade, who initially commissioned McArthur to plot Meadville. Served two terms in the Senate; was appointed Crawford County Prothonotary by Governor Snyder; and served as county Register and Recorder. He married Rebecca McLean, the daughter of his surveying instructor.