[1] Wallenberg became underlöjtnant in the Swedish Navy in 1882 but left his position the same year at the age of 18 and received a Candidate of Law degree from Uppsala University in 1888.

In addition, Wallenberg had been so intrigued by the promotion of Swedish industry that his name became intimately connected with its development in the first quarter of the 20th century.

Along with the Norwegian Sam Eyde, he founded Norsk hydro elektrisk kvælstofsaktieselskab in 1905, whose facilities at Notodden in Norway have been epoch-making for the extraction of nitrogen compounds from the air.

Wallenberg was the leading representative in Sweden of the modern pursuit of industry concentration under the leadership of the major banks.

[4] A stately testimony to the significance of his efforts in these various fields leaves the Ekonomiska studier, tillägnade Marcus Wallenberg på hans 50-årsdag ("Economic Studies, dedicated to Marcus Wallenberg on his 50th birthday", 1914), a festschrift authored by about thirty collaborators in the field of practical and theoretical economics.

[2] Wallenberg, who was widely used for committee assignments in banking legislation and related matters, was from 1917 a member of the Trade Council (Handelsrådet).

The agreements, which were now signed on 29 May 1918 with England, France, the United States and Italy and which assured Sweden of the supply of food and other necessities against the leasing of tonnage to the Triple Entente, and the restriction of exports to the Central Powers, were primarily Wallenberg's work.

Wallenberg participated in leading positions in the implementation of the Dawes Plan, and was the sole permanent arbitrator in disputes concerning the interpretation and application of the law, the financial burden on German industry and was a member of the permanent arbitration tribunal for disputes concerning the Dawes Plan application.