During the Berlin Conference negotiations in 1884-1885, which divided Africa among the European colonial powers, the US sought to protect its commercial interests in Africa through diplomacy rather than direct military intervention. While US strategy was inclined towards increasing its influence overseas, it was generally felt that this was best accomplished by remaining neutral in disputes among European powers. At the time, the US had no overseas possessions, and wouldn't have any until the Spanish-American war in 1898.

Furthermore, this was just two decades after the US Civil War. There was a general reluctance towards war in general, as well as distaste in some quarters at the idea of white men killing each other over African affairs.

Munene, G. Macharia. “THE UNITED STATES AND THE BERLIN CONFERENCE ON THE PARTITION OF AFRICA, 1884 – 1885.” Transafrican Journal of History, vol. 19, 1990, pp. 73–79. JSTOR, www.jstor.org/stable/24328676. Accessed 16 Apr. 2020.