In early October 1861, United States warships entered the Head of Passes, where the Mississippi River’s multiple entrances converge into a single channel. The occupation simplified the blockade by enabling a handful of ships to seal off the “father of waters” and cut off supplies to New Orleans. Confederate Capt. George N. Hollins recognized the danger, assembled a makeshift flotilla, and launched a surprise attack on the enemy vessels. Neil P. Chatelain’s Ironclad Ambush: Confederates Strike Lincoln's Mississippi River Blockade at the Head of Passes, October 12, 1861, is the first book-length treatment of this pivotal naval action.The Battle of the Head of Passes on October 12 marked the Civil War’s first major fleet engagement. The Southern privateer ironclad ram Manassas rammed USS Richmond, and as the Federals retreated toward the Gulf, two blockaders ran aground and crews abandoned ship as Confederate gunboats closed in. The clash represented the Confederacy’s first major naval victory, the first use of an ironclad in North American waters, and the first direct challenge to Abraham Lincoln’s blockade. The battle quickly became mired in confusion and conflicting accounts. Outdated technologies—sailing ships, fire rafts, and rams—collided with modern innovations like screw-propelled steamers, telegraph communications, and ironclads. The fog of war led officers and enlisted men to misinterpret orders, as many historians have misinterpreted the facts. Some commanders excelled and earned promotions; others faltered, appeared drunk, or suffered breakdowns.Lingering questions persist: Why did U.S. forces initially enter the Head of Passes? Why did Hollins seek to counter them? Which ships were involved? Why did two blockading crews abandon their vessels mid-battle? Why did the Confederates withdraw yet claim victory? And why does this seemingly minor, often-overlooked engagement matter?Award-winning historian Neil P. Chatelain’s Ironclad Ambush scrutinizes every previous account of the battle, firsthand archival material, and period newspapers. Drawing on voices from all sides—including ship captains, junior officers, enlisted sailors, lighthouse keepers, and civilians across southeastern Louisiana—he unravels the complexities and contradictions of early Civil War coastal and riverine naval operations. Everyone with an interest in naval warfare will find this book invaluable.