 Ramba uchiverenga ndima iyi - Pakutanga kweHondo Yenyika Yose, Leggett akashanda somuzvipiri muboka reshamwari yake, Major General George B. McClellan kumadokero kweVirginia. Akabatsira kusimudza 78th Ohio Infantry Regiment uye akagadzwa semutungamiri wayo munaJanuary 1862. Akatungamirira chikwata chake muhondo dzeFort Donelson, Shiloh, neKorinde. Muna November 1862, akagadzwa kuva brigadier general wevanozvipira uye akabatanidzwa muVicksburg Campaign, achitambura maronda anorwadza. Mushure mokunge apora, Leggett akatungamirira 3rd Division ye XVII Corps munguva yeAtlanta Campaign uye Shermans March to the Sea. Akanga ari mukuru mukuru wevazvipiri muna July 1864, uye akatumwa semukuru mukuru gore rakatevera. Chiito chake chokupedzisira chaiva muCarolinas Campaign mukati mechirimo cha1865. 