The remarkable effectiveness of the British army from Crimea to the Boer War reflected an institutional culture almost perfectly adapted to Victorian soldiers’ social origins, the tasks they were called upon to perform, and the colonial arenas in which they were asked to perform them, but also a culture increasingly out of step with its own society and evolving military technologies, methods, and challenges. Instead, fortified by the army’s success at its colonial tasks, and despite efforts by politicians and even some of the army’s own brightest intellectual lights, it survived – one might almost say defied – one institutional reform after another, until in South Africa in 1899, a string of calamitous defeats at the hands of what amounted to well-armed farmers upended both the army’s confidence and that of the British people in its professional competence. The institutional soul-searching that followed finally began transforming the British Army from what had become in many ways a military anachronism into a modern fighting force. That transformation came just in time to enable it to survive the bloody opening engagements of World War I and in the process help avert the rapid and decisive defeat of the Allied armies in France.

The American Civil War presented an exceptional state of affairs in modern warfare, because strong personalities could embed their own command philosophies into field armies, due to the miniscule size of the prior US military establishment. The effectiveness of the Union Army of the Tennessee stemmed in large part from the strong influence of Ulysses S. Grant, who as early as the fall of 1861 imbued in the organization an aggressive mind-set. However, Grant’s command culture went beyond simple aggressiveness – it included an emphasis on suppressing internal rivalries among sometimes prideful officers for the sake of winning victories. In the winter of 1861 and the spring of 1862, the Army of the Tennessee was organized and consolidated into a single force, and, despite deficits in trained personnel as compared to other Union field armies, Grant established important precedents for both his soldiers and officers that would resonate even after his departure to the east. The capture of Vicksburg the following summer represented the culminating triumph of that army, cementing the self-confident force that would later capture Atlanta and win the war in the western theater.