A great many commanders in the American Civil War (1861–1865) served in the Mexican War (1846–1848). Civil War Leadership and Mexican War Experience explores the influence of the earlier war on those men who would become leaders of Federal and Confederate forces. Military historian Kevin Dougherty sets the context with a discussion of professional soldiering before both wars. He then depicts the unique experiences of twenty-six men in Mexico, thirteen who would later serve the Confederacy and thirteen who would remain with the Union. He traces how tactics they used and reactions they had to Civil War combat reveal a remarkable connection to what they learned campaigning against Santa Anna and other Mexican generals.

Personalities discussed range from well-known leaders such as Ulysses S. Grant to lesser-known figures such as John Winder; from geniuses such as Robert E. Lee to mediocrities such as Gideon Pillow; and from aged heroes such as Winfield Scott to developing practitioners such as William Sherman. No other volume so exclusively and thoroughly focuses on connections of service in both wars.

Two appendixes in the book list 194 Federal generals and 142 Confederate generals who served in Mexico. The impact of these experiences on major tactical decisions in the Civil War is far-reaching.