Wahlberg earned success and was awarded with medals at the Paris Salon in 1870 and 1872. At the 1878 World's Fair in Paris, Wahlberg was recognized with a first class medal. Wahlberg was credited for bringing the then modern techniques of landscape art to Sweden. Almost every summer he made a short return to Sweden to study the nature in places such as Stockholm archipelago, Skåne, Halland, and Värmland. He died on 4 October 1906 in Tranås.