A pioneer of foreign direct investment in the early modern period, De Geer is considered to be both the father of Swedish industry for introducing Walloon blast furnaces to Sweden and the father of the Swedish slave trade for pioneering Sweden's involvement in the Atlantic slave trade.

[1][8] The Swedish government continued to support him and De Geer received the official monopoly on the copper and iron trade in Sweden.

Thanks to his accrued wealth and status as a noble, De Geer was able to purchase three-quarters of leased farmlands on his Östergötland estates.

The fleet contained thirty-two fully manned ships each with a full marine complement, with which Sweden was able to capture the island of Fehmarn.

In 1650, an expedition by slave trader Hendrik Carloff on behalf of the company founded the Swedish Gold Coast to conduct trade with local African kingdoms.

[7][6][10][11] In 2014, Swedish artist Carl Johan De Geer (a direct descendant of Louis) organized an exhibition about him in the city of Norrköping, Sweden, titled "Reflections on the barbaric 17th century".

In an Norrköpings Tidningar article, Carl noted how the legacy of his ancestor had impacted him, noting that he had been publicly confronted about Louis' involvement in slave trading in addition to receiving a phone call asking whether or not he would be interested in renovating Fort Carolusborg, a Ghanaian slave castle constructed by the Swedish Africa Company.

Carl also received a phone call from a Brazilian man with the De Geer surname whose ancestors had been enslaved and transported by the Swedish Africa Company to Brazil.

In response to these developments, Carl publicly made plans to construct a miniature model of Fort Carolusborg in Norrköping, as part of an effort to overturn a "romanticized view of the Swedish 17th-century".