Bio from "History of South Dakota" by Doane Robinson, Vol. I (1904), pp 728-729.

PETER OSCAR OLSON was born on the homestead farm, on section 28, township 94, range 54, Yankton county, South Dakota, on the 1st of February, 1874. His father, Christian Olson, is a native of Norway, having been born at Biri, near the historic and beautiful old city of Christiania, on the 16th of December, 1846, and having been there reared to maturity. In 1866 he emigrated to America and made his way to Wisconsin, where he remained until the spring of the following year, when he came to the great territory of Dakota and took up a claim of government land in Yankton county, the same being the homestead on which the subject of this sketch was born. He continued to reside on this place until 1901, when he removed to another farm, which he had recently purchased, one and one-half miles distant from the old homestead, and there he still resides, being one of the honored pioneers and prosperous and influential farmers of the county. In 1873 was solemnized his marriage to Miss Thea Louise Bagstad, who was born in Vernon county, Wisconsin, January 23, 1856. In 1867 she accompanied her parents on their removal from the Badger state to Yankton county, Dakota, where she was reared to womanhood and where her marriage was solemnized. Of this union were born four children, namely: Peter O., Carl M., John B. and Laura C., the last mentioned being deceased. Mrs. Olson was a devoted wife and mother and her gracious personality endeared her to all with whom she came in contact, while she exemplified her Christian faith in her daily walk and conversation. While visiting her sister, at Hamline, Minnesota, she was attacked with an illness which terminated in her death a few days later, on the 23d of May, 1888. 

The subject of this sketch was reared to the sturdy discipline of the home farm and his early educational training was secured in school district No. 7, being supplemented by four terms in the preparatory department of Yankton College. He has always been fond of reading, particularly books of an historical nature, and this appreciation has led him to add materially to his store of information, as has also his active identification with the practical affairs of life. Mr. Olson has never abated his allegiance to the great basic art of agriculture, of whose dignity and value he is fully appreciative and through the same he has attained a success worthy the name. He is fond of outdoor work and early decided-that the work of the farm offered the safest and surest method of obtaining a livelihood and a position of independence. He and his two brothers have always worked together with their father, believing that "in union there is strength," and in evidence that their view has been authorized we may say that since 1890 they have purchased six hundred and forty acres of land and expended several thousands of dollars in improving the same, despite the fact that they encountered no few obstacles and discouragements, including the protracted drought in 1894, causing a total failure of the corn crop; a hail storm in 1896, entailing a similar result; and a flood in the following year, causing a small crop in all lines. Mr. Olson is a young man of distinct individuality and strong convictions, and he believes that if a young man is to succeed on the farm he must use business principles, must be on time and make each day count, not waiting for the morrow, while he also maintains that resorting to saloons and gambling dens will accomplish the failure of any and every man. He is an uncompromising Republican and has been zealous in advocating the party cause whenever Opportunity has presented. In 1888-9 he served as treasurer of school district No. 7, having been appointed to fill a vacancy. His religious faith is that of the Lutheran church, and he holds membership in the church near Mission Hill, one of the oldest in the state. 

At Gayville, Yankton county, on the 24th of October, 1901, Mr. Olson was united in marriage to Miss Bergine Marie Olson, who was born at Biri, Norway, February 2, 1883, and who came to Yankton county on the 20th of April, 1898, accompanied by her sister Julia. Her parents, Martinus and Karen (Nilson) Olson, became residents of this county in May, 1899, and still maintain their home here. They are the parents of eight children, all of whom were born in Norway except the youngest, their names, in order of birth, being as follows: Nils, Pergine M., Julia, Oluf, Adolph, Peter, Sigurd and Clara L. The subject and his wife are the parents of a winsome little daughter, Laura Caroline, who was born on the 6th of August, 1902.