Sveinn Jónsson was born in Skagafjarðarsýsla on August 5, 1867. He died on September 17, 1946 in Mountain, N. Dakota.
Spouse: August 15, 1896 Kristjana Ragnheiður Kristjánsdóttir b. in Snæfellsnessýsla on June 25, 1877.
Children: 1. Jón b. December 2, 1897 2. Kristján b. December 24, 1898 3. Guðmannía Ágústa Jóhanna b. October 7, 1900 4. Jónatan b. July 26, 1903 5. Rögnvaldur b. September 9, 1905 6. Sveinn b. August 5, 1909 7. Þorgerður b. April 3, 1912 8. Guðmundur Theodore b. December 28, 1914 9. Kristín Esther Lilja b. July 10. júlí 1916.
Sveinn was the son of Jón Jónsson and Þorgerður Jónatansdóttir from Brenniborg in Skagafjarðarsýsla, who came west to New Iceland in 1876. Kristjana was the daughter of Kristján Guðmundsson and Ragnhildur Bjarnadóttir in N. Dakota. Sveinn moved from New Iceland to Mountain, N. Dakota where he met and married Kristjana. They lived their lives there and Sveinn worked for the government.