Ethnicity: His father, Gabriel Kalm, is Finnish, while his mother, Katarina Ross, is believed to be of Scottish ancestry
Pehr Kalm was born in Ängermanland, Sweden, on the 6th of March in 1716. His family, who came from Korsnäs in the Närpiö district of Finland, had fled there during the Great Northern War. His father, who had been assistant pastor in his home parish, died during their flight at the time of the boy's birth, and Pehr's mother, who came from a merchant family in Vaasa, returned after the war to Vöyri in Ostrobothnia. Although he was brought up in poverty, he was able to enter Vaasa Grammar School in 1735 and matriculated to Turku Academy in 1735. There he studied under the supervision of the utilitarian mineralogist Herman Diedrik Spöring and the naturalist Carl Linnaeus, Johan Browallius and Carl Fredrik Mennander. He tutored at Lieksa and Kitee, Finland in 1738 and 1739, noting the natural history of the country.
Kalm took a lot of research trips and the first of which was to Savo and Karelia in spring 1740. In December 1740 Pehr Kalm enrolled at the University of Uppsala.The Academy of Sciences was planning to send Kalm to a trip to look for new plants suitable for cultivation and Bielke and Kalm made a journey to Moscow via the Baltic provinces and St. Petersburg and also travelled about in Ukraine.
Linnaeus began to plan an expedition to North America in order to collect information on economically useful plants that might be viable in Scandinavia, and the Academy decided to send Kalm to there. Kalm made careful preparations for his research trips. Especially in the winter of 1741 - 42, when talk of a large Academy project began, he started reading accounts by his predecessors and making a list of the things to be observed during his travels.Guided by Linnaeus, he immersed himself energetically in botany, and he studied the determination of latitude and longitude, attending lectures by the astronomy professor Anders Celsius.
Kalm sailed for England in November 1747 and remained there for some months.He reached Philadelphia in September 1748, where there were a lot of descendants of the Swedish colony established in 1638. Kalm relates, however, that the first person with whom he became acquainted was Benjamin Franklin, who was then Postmaster in Philadelphia. On the advice of his acquaintances, Kalm delayed his departure for the North because of the advent of winter. News of this did not please Linnaeus and other members of the Academy of Sciences, because they wanted Kalm to familiarize himself with areas where the climate was similar to that of Sweden. Kalm spent most of the winter of 1748 - 49 at Raccoon, but he also acquainted himself with the vegetation of New Jersey and visited New York.
The main part of Kalm's trip began in May 1749. He travelled up the Hudson River to Albany and continued into French Canada as far as Montreal and Quebec. At Cap aux Oyes to the north of Quebec, the travellers turned back, since the region was too restless because of the Indians. The French treated Kalm almost like royalty, because the voyage had been thoroughly prepared by the diplomats. For the winter, Kalm retraced his route to Raccoon, but in summer 1750 he was offered a new opportunity to travel to Albany via the Great Lakes region. Amongst other places, he visited the Niagara Falls. His superb description of the Falls was immediately published in the Pennsylvania Gazette, of which Franklin was the editor, and later in European journals as well.
Before his Niagara trip, Kalm spent the winter of 1749 - 50 at Raccoon, working on his materials. During this time important things happened in his personal life as well: he got married to Anna Margareta Sjöman, who met at Raccoon.
Kalm sailed for Europe in February 1751, reaching Stockholm in May and late that year he returned to the University of Uppsala to the post of Professor of Economics. There he remained for the rest of his life teaching, and publishing.
He established an experimental garden. At first this was in the grounds of his own house in Turku, but in 1752 he was also given a farm at Hirvensalo for this work. Turku did not acquire proper university gardens - the 'Bishop's House' property - until 1752, again largely thanks to Kalm.
Kalm was one of the outstanding utilitarian Linnaeus botanists, one genus and 90 species of plants being named for him. His major legacy, his book, stimulated natural history in Sweden and provided Europeans with an accurate and wide-ranging account of North American conditions and customs.