In the early 1900s, the United States was a place where blacks in the south were systematically disenfranchised by Jim Crow laws and faced daily the threat of violence. The U.S. Army allowed black men to serve as soldiers and non-commissioned officers, and on rare occasions commissioned officers, but institutional racism persisted, and a clear color line prevailed. From 1910 to 1942, black American officers volunteered for a complex and risky enterprise to train and command forces in Liberia, a country founded by freed black American slaves. These officers performed their duties as instruments of imperialism for a country that was, at best, ambivalent about having them serve under arms at home and abroad. African American Officers in Liberia: A Pestiferous Rotation, 1910-1942 by Brian G. Shellum tells the story of seventeen African American officers who trained, reorganized, and commanded the Liberian Frontier Force, whose purpose was to defend Liberia from partition by its colonial neighbors and subjugate the local indigenous groups. The endeavor was financed by the U.S. but directed by the Liberian government. Essentially, the United States extended its newfound imperial reach and policy of "Dollar Diplomacy" to Liberia, a country it considered a U.S protectorate. Shellum explores U.S. foreign policy towards Liberia and the African American diaspora, while detailing the African American military experience in the first half of the twentieth century. Shellum brings to life the story of the African American officers who carried out a dangerous mission in Liberia for an American government that did not treat them as equal citizens even in their homeland, and provides recognition for their important role in preserving the independence of Liberia.