Great friendship existed between the United States and Imperial Russia during the nineteenth century. The Old World Russian autocracy supported the young New World democracy because of the emerging U.S. role as a bulwark against Great Britain’s ambitions, in Asia and in the North Pacific Ocean region especially. In fact, when the American Civil War threatened to divide the United States, Russia alone among the European great powers gave no aid or comfort to the seceding states. The surprise 1863 arrival of squadrons of Russian warships and thousands of Russian sailors in New York and San Francisco proved fortuitous, coming when the Union feared British and French intervention on the Confederacy’s behalf. C. Douglas Kroll, using both Russian and U.S. documents, investigates why the Russian Pacific Squadron came to San Francisco, a port of departure for California and Nevada gold headed east; what happened during its nearly year-long visit; and how its presence influenced events. With the units of the U.S. Navy’s small Pacific Squadron widely dispersed and Confederate commerce raiders on the loose, the Russians’ arrival suggested to on-lookers that they intended to defend the Union against interference. Whether actively supporting the Union or training and refitting or both, the Russian officers and sailors endeared themselves to San Francisco’s citizens. Parades and balls, as well as dinners hosted by both sides, helped San Franciscans overlook the various differences they had with their Russian visitors. Kroll gives us a thorough examination of the Russians’ visit and its social, diplomatic, and military impact.