His father, Måns Jönsson, married to Sara Carlsdotter, owned a small farm and worked as a parish tailor in Smedstorp.

In the Riksdag, he distinguished himself as a brilliant orator (although he most probably had attended only three classes of primary school) and a champion of liberalism, who fought for equal rights for the Jews, for allowing foreigners to hold professorships at Swedish universities, for land reform (proposing to dismember huge estates belonging to the Church of Sweden) and for extending the railway net.

He left his wife Ingar Jönsdotter and their seven children, and fled to the United States with his mistress (a Stockholm waitress, Lovisa Jansdotter Carlén) and their illegitimate infant son Carl in 1859.

Around 1862, these two and a third son (August Olsson) emigrated to the United States, answering a request for help from their father who had lost an arm in a sawmill accident in 1861.

Per came to live on the family farm in Minnesota, but Måns joined an Illinois unit of the Union Army in the American Civil War following which he returned to Sweden.