Sean McLachlan worked for ten years as an archaeologist before becoming a full-time writer. He has published several books on history and travel and divides his time between Missouri, England and Spain. He has a special interest in the understudied Trans-Mississippi theater of the American Civil War. His website is www.seanmclachlan.com

Gerry Embleton has been a leading illustrator and researcher of historical costume since the 1970s, and has illustrated and written Osprey titles on a wide range of subjects over more than 20 years. He is an internationally respected authority on 15th and 18th century costumes in particular. He lives in Switzerland, where since 1988 he has also become well known for designing and creating life-size historical figures for museums. His son Samuel is also an illustrator, and this is their third joint project for Osprey.

While the giant armies of the Union and the Confederacy were fighting over cities and strategic strongholds, a large number of warriors from both sides were fighting, smaller, more personal battles. Beginning with the violent struggle known as "Bleeding Kansas" armed bands of irregular fighters began to wage war in every corner of the United States. Many of the names of their commanders have become legendary: William Quantrill, "Bloody Bill" Anderson, and John S Mosby "The Grey Ghost". To their own people they were heroes; to others they were the first of a new generation of wild west outlaw. Their tactics included robbing banks, kidnapping soldiers & civilians, rustling cattle, and cutting telegraph lines. In fact, it is during the violence of the war that many of America's future outlaw legends would be born, most notably Cole Younger and Frank and Jesse James.