He was a driving figure in the introduction of Swedish agricultural land reforms (Enskiftet) which made possible large-scale farming with its economy of scale.

[2][3] [4][5][6] Macklean was born on 28 July 1742 at Ström Manor, Hjärtum parish, Bohuslän to Baron Rutger Macklier (1688–1748) and Vilhelmina Eleonora Coyet (1719–1778).

In accordance with feudal procedures of tenant land-right inheritance the manor had been divided, in the course of its existence, into hundreds of narrow strip allotments.

Agriculture on the approximately 7,000 acres was poorly managed, productivity was very low and the subordinate farmers mostly indebted.

Despite strong resistance from the tenant farmers and considerable financial difficulties, he basically implemented his plans in a few years.