Born in 1920 at Inverness, Nova Scotia, MacArthur was a municipal councillor for 18 years and served as Warden of Inverness County.[2] He entered provincial politics in the 1988 election, defeating Progressive Conservative incumbent Jim MacLean by 801 votes in the Inverness North riding.[3] In 1993, MacArthur defeated Inverness South MLA Danny Graham for the Liberal nomination in the re-established Inverness riding, after their ridings were eliminated through redistribution.[4] In the 1993 election, MacArthur was re-elected, defeating his closest opponent by 2860 votes.[4][5] He did not reoffer in the 1998 election.[6] MacArthur died in Inverness on February 24, 2010.[2][7][8]