At the age of nine, he became an orphan, and was looked after by the parish officers and sold at child auction, where they offered children at sale.

Then he became known as a prominent figure of the Scanian Socialists, he boycotted by several employers and returned to his home town, Ystad, where he opened a shoemaker with his partner Anders Nordstrand.

Thorsson was elected to the Lower House of the then bicameral Parliament of Sweden in 1902, and was regarded as the most radical of the Social Democrats.

In 1909 he became a member of the State Committee, then headed by Karl Staaf, with special responsibility for the military defence, and was also appointed Deputy Chairman of the Parliamentary Trustees.

elected chairman of the Social Democratic party, but he was not officially recognised as such before falling ill and dying in May of that year.

Ernst Wigforss in his memoirs states that Thorsson firmly believed that Rickard Sandler, who had served as prime minister since Branting fell ill in January, was the most suitable candidate for party chairman.