In 1740 he gained the patronage of Friherre Sten Carl Bielke who took him to live on his estate near Uppsala, at which university Kalm matriculated on 5 December 1740. Here his teachers were Linnaeus and Anders Celsius. Their example and the support of Bielke, who was keenly interested in natural history, particularly as applied to agricultural improvement, led to Kalm's undertaking several journeys for research purposes between 1740 and 1745 through Finland, Sweden, Russia, and Ukraine.
He graduated doctor of natural history and economics of Abo Academy [in the Swedish-speaking part of Finland] in 1746 and became on 31 August 1747 its first professor of oeconomie, a subject which included mineralogy, botany, zoology, and chemistry, and their economic application. At the instigation of Linnaeus, who had himself hoped to make the journey, and with the support of the Abo Academy, Kalm travelled in North America between 1747 and 1751 with explicit instructions to gather information and specimens such as seed which would be of practical economic use to Sweden.
Here is an excerpt from the diaries Kalm kept while in America. We found it in
The America of 1750: Peter Kalm's Travels in North America,(1964). These mention, among the animals he saw, some felines,".... probably a species of cat-lynx, or perhaps a kind of panther; foxes of various kinds, raccoons,...."
His biography continues:
He visited Philadelphia, where on 1 January 1750 he married Anna Margareta (d. 1787), daughter of Johan Sjoman, commissioner at the Stockholm arsenal, and widow of John Sandin, dean of the Swedish congregation in Philadelphia. He was warmly received into the leading scientific circles in Philadelphia. He then went on to Canada, where he arrived in the summer of 1749, and travelled extensively in areas of British and French settlement. He was particularly well received in New France, then the focus of much French scientific attention. He reached home in 1751, having been away four instead of the projected two years. He brought back plants and seeds of medicinal use and of benefit to agriculture and industry. All were planted enthusiastically, notably in his new botanical garden at Abo. Although few flourished the practice of systematic cultivation and experiment with plants gained wide currency among the well educated and the well born and his efforts were in this way very influential.
His fame derives not just from his dedicated studies but his espousal of his teacher, Linnaeus's ideas.