Isaac was employed as a clerk in Birmingham, Warwickshire, England. He (age 34) and his wife Maria were in Gardner's party of 1820 Settlers onboard the ship 'Sir George Osborn'. It is believed that their son John was born on the voyage. They arrived in Algoa Bay, Cape Colony, in July 1820. The Dugmores, with other members of Gardner's party, were located on the Kariega River (in Kariega Valley), about 12 miles south-west of Grahamstown (elsewhere recorded as 14 miles west of Grahamstown), just off the present National road to Port Elizabeth. The site of their farm is on the present farm 'Mosslands'.
The family knew hardship and hunger, and finally Isaac Dugmore took employment as a book-keeper to Messrs. Wood Bros. in Grahamstown. Maria willingly accepted her part, cared for the family, and ran the farm with the aid of her two elder boys, barely in their teens. There was no schooling for the children.