Mary Corp was born 16 Aug 1807 in Brewham, Somerset, England. She was christened on 25 Oct 1807 at St. John the Baptist Church. Her parents are William and Ann Newton Corp. Her first husband James Arnold died 14 Dec 1849 in Corsley, Wiltshire, England. She then married Stephen Sumner on 24 Feb 1851 at St. Nicholas Church, Bristol, Somerset, England. She moved to USA with her husband and two daughters Elizabeth and Mary Arnold in 1852. They first lived in Ohio, then Illinois and then to Minnesota. They first appear in the 1857 state census for Zumbro, Wabasha Co., MN. They lived there until her husband died in 1879.
After her husbands death in 1879 she moved to her son James Arnold's home in Olmstead Co., MN. She died in Farmington Twp., Olmstead Co., MN on 14 Aug 1887 and is buried in Farm Hill Cemetery.