Together with his business partner and friend Georg Heinrich Sieveking he led one of the largest trading firms in Hamburg during the second half of the 18th Century.
Other than making friends with Georg Heinrich Sieveking, whom he met as an adolescent in the Kontor of his father's firm, Voght was more inclined at this point in his life to dedicating himself to studying literature, politics, and science, and found little pleasure in his vocation as a merchant.
After a side trip to Pompeii, Naples, and a short stop in Venice, Voght traveled to Bergamo, where he made contact with the local silk weavers for his father's business.
Together, they made use of the newly independent English colonies to build up strong mercantile ties with traders in ports along the North American coast.
A good will missive dated March 29, 1783 was presented to Congress in Philadelphia on behalf of the Hamburg Senate by Johann Abraham de Boor.
After a trip to England in the winter of 1785–6, where he tried to familiarize himself with the local landscape architecture and modern methods of husbandry, he began work on his Hamburg estates on a model farm and arboretum (the present day Jenisch Park was his parc du midi).
Voght recruited two landscape gardeners for Flottbek renowned in Europe: the Scotsman James Booth and Frenchman Joseph Ramée.
The most prominent student of this academy was Johann Heinrich von Thünen, who would later correspond with Voght primarily about questions of crops yields of soils.
In contrast to the prevailing mode of providing for the poor, which was usually ecclesiastical and focused on moral and spiritual aspects of the situation, the reform was directed towards the economic needs of those affected.
In 1801, the Emperor summoned him to Vienna, in order to suggest remedies and help prepare plans for a reform of the poor provisions in that city.
During a many-month stay in Paris in 1807, he prepared a report commissioned by the French interior ministry on the situation of the Parisian poorhouses, orphanages, maternity houses, and prisons.
During the period of the Continental System he undertook another multi-year trip through Switzerland, France, and Italy, during which he got to know the Emperor Napoleon and his first wife Josephine in Paris.